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News Article | February 17, 2017
Site: www.eurekalert.org

Home to an immense diversity of marine life, the deep ocean also contains valuable minerals with metals such as nickel, copper, cobalt, manganese, zinc, and gold, and rare-earth elements used in electronic technology like smart phones and medical imaging machines. As demand for these resources increases and supplies on land decrease, commercial mining operators are looking to the deep ocean as the next frontier for mining. What are the risks and environmental impacts of deep-sea mining on fragile marine ecosystems? Would seafloor mineral resources be enough to keep up with the evolving demands of modern society? A panel of scholars including Stace Beaulieu, a deep-sea biologist at Woods Hole Oceanographic Institution (WHOI), will discuss these and other questions during the symposium, "Should We Mine the Seafloor?" scheduled on Saturday, February 18, at the AAAS meeting in Boston, MA. A news briefing for science journalists will be held at 4 p.m. on Friday, February 17, in room 103 of the Hynes Convention Center. The speakers will examine the pros and cons of seafloor mining, its engineering feasibility, and its legal and societal implications with the goal of providing the best available, objective, scientific evidence to inform ongoing policy efforts on this important and timely topic. "Our panel is unique in that we bring together knowledge of the demand for critical metals and the potential supply from known and yet-to-be-discovered seafloor mineral resources, and an understanding of deep-sea ecosystems, including a new perspective on ecosystem services that contribute to human well-being," Beaulieu says. Currently, there's no mining occurring in the ocean deeper than the continental shelves, but the industry is moving forward quickly. Many of the engineering challenges associated with working in the deep sea have already been addressed by the offshore oil and gas industry. Different types of machines for mining have been built and the components for mining systems are currently being tested in deep-sea deployments. About 27 countries have already signed contracts to explore for deep-sea resources with the International Seabed Authority (ISA), the organization that controls mineral exploration and exploitation in the area beyond national jurisdiction. And the first deep-sea mining project --Solwara 1 within the jurisdiction of Papua New Guinea--is scheduled to begin in 2019 by Nautilus Minerals. Beaulieu's talk will address potential environmental impacts from deep-sea mining and highlight new research on the vulnerability and resilience of deep-sea ecosystems. She's also been working with social scientists to address the question of economic impacts from lost and degraded ecosystem services, such as the potential for new medicines from deep-sea, biological resources. The symposium will also feature talks by experts Thomas Graedel, an industrial ecologist at Yale University, and Mark Hannington, a geologist at GEOMAR-Helmholtz Center for Ocean Research. Graedel will examine how the demand for metals might evolve in the next few decades. Hannington's talk will focus on estimates of the abundance of seafloor deposits targeted for mining. The symposium will be moderated by Mindy Todd, a radio producer and journalist at WCAI - The Cape & Islands NPR Station. Should We Mine the Seafloor? The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment. For more information, please visit http://www. .


News Article | October 26, 2016
Site: www.eurekalert.org

Portable observatories and new marine vehicles: The hinge of historic change in deep sea exploration Five hundred vents newly discovered off the US West Coast, each bubbling methane from Earth's belly, top a long list of revelations about "submerged America" being celebrated by leading marine explorers meeting in New York. "It appears that the entire coast off Washington, Oregon and California is a giant methane seep," says RMS Titanic discoverer Robert Ballard, who found the new-to-science vents on summer expeditions by his ship, Nautilus. The discoveries double to about 1,000 the number of such vents now known to exist along the continental margins of the USA. This fizzing methane (video: http://bit. ) is a powerful greenhouse gas if it escapes into the atmosphere; a clean burning fuel if safely captured. "This is an area ripe for discovery," says Dr. Nicole Raineault, Director of Science Operations with Dr. Ballard's Ocean Exploration Trust. "We do not know how many seeps exist, even in US waters, how long they have been active, how persistent they are, what activated them or how much methane, if any, makes it into the atmosphere." Further research and measuring will help fill important knowledge gaps, including how hydrocarbons behave at depth underwater and within the geological structure of the ocean floor. Expeditions this year include also NOAA's Deepwater Exploration of the Marianas Trench - a 59-day voyage with 22 dives into the planet's deepest known canyons in the Pacific Ocean near Guam. NOAA explorers added three new hydrothermal vents to the world's inventory and a new high-temperature "black smoker" vent field composed of chimneys up to 30 meters tall - the height of a nine-story building. Also revealed: a tiny spot volcano (the first ever discovered in US waters), a new mud volcano, thick gardens of deep-sea corals and sponges, a rare high-density community of basket stars and crinoids (a living fossil), and historic wreckage from World War II. (Photo, video log: http://bit. ) Scores of spectacular, rare and sometimes baffling unknown species encountered on this year's first-ever voyages to new deep ocean areas include several purple animals such as: Beyond being spectacularly photogenic, such animals help scientists better understand the web of life that sustains all species, including humans. As well, understanding how "extremophile" lifeforms survive in such conditions (piezophiles, for example, thrive in high pressure; pyschrophiles, aka cryophiles, live in water as cold as ?20 °C, as in pockets of very salty brine surrounded by sea ice), is usefully relevant to food and pharmaceutical preservation technologies, medical technology, nanotechnology and energy science. Dr. Ballard and about 100 other leading figures in marine science meet Oct. 20-21 to compare thoughts on the future of marine exploration at the 2016 National Ocean Exploration Forum, "Beyond the Ships: 2020-2025," hosted in New York by The Rockefeller University in partnership with Monmouth University. The Forum is also supported by the Monmouth-Rockefeller Marine Science and Policy Initiative, NOAA, the Schmidt Ocean Institute, and James A. Austin, Jr. Ocean exploration has arrived at a historic hinge, Forum organizers say, with profound transformation underway thanks to new technologies, led by increasingly affordable "roboats" - autonomous or remotely controlled vehicles that dive into the ocean or ply the surface laden with sensors collecting information from instruments suspended beneath them. ROV SuBastian, for example, is a new eco-friendly 3,100 kg (6,500 pound) deep-sea research platform for the Schmidt Ocean Institute's R/V Falkor, equipped with ultra high-resolution 4K cameras, mechanical arms that move seven ways and can sample to depths of 4,500 meters (2.8 miles), with a lighting system equivalent to the lamps of 150 car high-beams. (SuBastian sea trials video: http://bit. High-res photos, b-roll: http://bit. ). Says Wendy Schmidt, co-founder of Schmidt Ocean Institute: "With ROV SuBastian we will help make life on the ocean floor real to people who will never visit the sea, so they, too, can begin to appreciate the importance of ocean health and make the connection between life in the deep sea and life on land." "You don't have to be a scientist at sea to recognize the importance of the marine environment, and we are only at the beginning of our understanding. We never anticipated discovering the world's deepest living fish, the ghostfish (video: http://bit. ), back in 2014, and are excited about the life we will discover next." ROV SuBastian will have that opportunity this December during its first science cruise, in the Mariana Back-Arc in the western Pacific. (Cruise details: http://bit. . All dives will be live-streamed on Schmidt Ocean Institute's YouTube page: http://bit. ). Contributing as well to the transformation: Modern communications and sampling techniques, including eDNA, big data analysis and other high-tech advances that automate and vastly accelerate the work, opening the way for experts and the public to reach, see, chart, sample and monitor formerly secret depths of the seas. Innovations include portable observatories for underwater monitoring and a "curious exploration robot," programmed to focus on everything unfamiliar to its data bank brain (photo: http://bit. , video: http://bit. , credit WHOI). According to innovator Yogesh Girdhar of the Woods Hole Oceanographic Institution, in a recent test off the Panama coast, a similar swimming robot discovered a startlingly enormous population of crabs. Other engineers, meanwhile, are developing "game changing" unmanned undersea and surface vehicles tricked out with an array of sophisticated sensors to perform a suite of underwater tasks, enabled to run for months by recent improvements in battery technology. (See video, for example, of Boeing's 51-foot Echo Voyager: http://bit. ). Such "roboats" can be programmed to conduct deep sea exploration or searches using a lawn mower pattern, surfacing regularly to report data back to shore via satellite, or to patrol a coastal area, returning to port after one or two months to recharge and redeploy. These technologies will enable today's generation to "explore more of Planet Earth than all previous generations combined," predicts Dr. Ballard, whose celebrated career will be recognized at the Forum with the Monmouth University Urban Coast Institute's Champion of the Ocean award. The technologies will not only help discover and monitor new mineral and living resources, they could help secure interests vital to the world's economy or identify the best paths for communications cables that span the ocean floor - the veins of the Internet. Until recently, ocean exploration has involved ships operated like fishing vessels, dipping sensors and hauling up data. Forum participants such as John Kreider of Oceaneering International envision such ships in future serving as hives from which flotillas and squadrons of autonomous underwater, surface and aerial vehicles are launched - robots guided by experts on board or remotely, such as from a distant university campus via "telepresence," returning with images and data orders of magnitude larger than ever before. Thanks to modern communication technologies, schoolchildren, their teachers and indeed any interested members of the public can, and do, now follow expeditions online in real time. Among the many compelling interests and pursuits of marine scientists and historians in the public, private and military sectors: Says scientist James (Jamie) A. Austin, Jr. of the University of Texas, "the slow, time consuming and expensive way we've done ocean exploration forever - one ship doing one task at a time - is giving way to autonomous systems that net massive hauls of data, with advances in big data analysis enabling scientists to make sense of it rapidly." Dr. Austin envisions installations on the seafloor - measuring tremors or helping scientists estimate the rate at which Earth swallows carbon into its mantle through plate tectonics, for example - with data delivered by a device periodically flying up and down to the surface. Simply mapping the ocean floor is an important goal. While satellites have fully charted the seafloor in low resolution, only 10% is mapped in detail. At an estimated cost of $2.9 billion - or about $9 per square kilometer ($23 per square mile) - a "Gurgle Earth" map of the deep oceans could be completed at high resolution using swath like, multi-beam sonar. The hazard of uncharted oceanic mountains, trenches, volcanoes and other features was dramatically underscored in 2005 when a nuclear attack submarine, the USS San Francisco, struck a seamount in the Pacific at high speed, killing one crew member and injuring 97. Over 50% of US territory lies beneath the ocean surface and such mapping could also expand American territorial and resource claims. With documentation of the continental shelf, America's Exclusive Economic Zone, 11.3 million square km in size today, could extend a further 2.2 million square km - a 20% enlargement, representing an underwater area larger than Alaska. (See http://bit. ). Other recent finds of ancient shipwrecks and even ancient human remains, he adds, reveal that early mariners didn't simply hug the coastline but sailed courageously great distances from shore, and make it possible to determine who they were. While these and countless biological discoveries represent things discovered underwater, the intent of future exploration campaigns include measuring more, sampling more, and better understanding physical, geological and living processes - knowledge of vital importance for security, responsible ocean use and sustainable resource management. Asked what he thought might yet be discovered underwater, Dr. Ballard compares that to asking Lewis or Clark what they thought they'd find on their historic traverse of America. The reply, he says, would have been "I don't know. I'm getting into a canoe and I'm going to paddle." In one of several papers written for the Forum, meanwhile, U.S. Ambassador Cameron Hume adds that, beyond exploring and the initial characterization of an ocean area, humanity also needs to pursue subsequent research and long-term observing. In his paper, Dr. Jerry Schubel of the Aquarium of the Pacific, lamenting the relatively low level of public attention accorded to ocean exploration, points to new opportunities for awareness raising created by social media. "Understanding life on other planets," he says, "may help us understand the origins of life in the universe, but it can't match the relevance and importance of ocean exploration to the future of life on this planet." Says organizer Prof. Jesse Ausubel, faculty member at The Rockefeller University: "SuBastian and the Roboats sounds like a rock band, but it is the future of ocean exploration. One million marine species and one million shipwrecks may remain to be discovered. Let's use new approaches to multiply exploration." Says Forum organizer Vice Admiral Paul Gaffney, former President of Monmouth University and Urban Coast Institute Ocean Policy Fellow: "America is the greatest maritime nation in the history of the world, yet we scarcely know submerged America and only about 10% of the global oceans. At this Forum, we are encouraging ocean technology leaders to join the discussion and support more comprehensive exploration campaigns indispensable for sustainable use of the oceans and inspiring ocean stewardship." The ultimate aim: to formulate compelling, feasible campaigns to be carried out by the participants in the 2020-2025 timeframe. At the Forum, Dr. Jyotika Virmani will share the roster of teams for the $7 million Shell Ocean Discovery XPRIZE, a global competition to promote unmanned ocean exploration. In a letter to the Forum (in full: http://bit. ), the President of the US National Academy of Sciences, famed ocean explorer Marcia McNutt, says "a number of events have underscored how essential our mission is to vastly improve knowledge of the marine environment." Inadequate knowledge of ocean terrain and currents hampered the search for flight MH 370 in 2014, for example. CubeSats, she notes, have "'democratized' space, providing access for pennies on the dollar. Similarly, new commercial tools, although still in their infancy, hold the promise of ushering in the citizen science era of ocean exploration." "The task we face is simply too large to continue to use 20th century tools if we hope to make a dent in the problem." Oct. 20-21Venue: The Rockefeller University, 1230 York Ave, New York, NY.Website, including Forum programme and speaker biographies: http://phe. Supporters: the Monmouth-Rockefeller Marine Science and Policy Initiative , NOAA, the Schmidt Ocean Institute, and James A. Austin, Jr. Positioning Ocean Exploration In a Chaotic Sea of Changing Media Jerry R. Schubel (Aquarium of the Pacific) http://bit. Exploring the Ocean through Sound Jennifer L. Miksis-Olds (University of New Hampshire) and Bruce Martin (Dalhousie) http://bit. Discussion Paper on Marine Minerals Mark Hannington, University of Ottawa, and Sven Petersen, GEOMAR Helmholtz Center for Ocean Research http://bit. Emerging Technologies for Biological Sampling in the Ocean Shirley Pomponi, Cooperative Institute for Ocean Exploration, Research, & Technology [CIOERT], Harbor Branch Oceanographic Institute, Florida Atlantic University http://bit. The Forum is the latest in a series mandated by Congress (Title XII of Public Law 111-11) in March 2009 when it officially established the NOAA ocean exploration program. This law requires NOAA to consult with the other federal agencies involved in ocean exploration, as well as external stakeholders, to establish a "coordinated national ocean exploration program" that promotes data management and sharing, public understanding, and technology development and transfer. The law also requires NOAA to organize an "ocean exploration Forum to encourage partnerships and promote collaboration among experts and other stakeholders to enhance the scientific and technical expertise and relevance of the national program." The 2016 Forum convenes approximately 100 experts from academia, government, and the private sector to discuss adaptation and integration of technologies that can be employed in ocean exploration campaigns in the 2020-2025 timeframe. The Forum will look to a future of expanded exploration activities by making more platforms capable of measuring, sampling, or imaging yet-to-be-explored areas - employing a suite of technologies that have been dubbed "flyaway systems." Expanding spatial coverage and reducing cost of data collection are key ocean exploration priorities over a ~10 year time horizon. These priorities can be realized by creatively adapting and assembling existing technologies, and deploying them onboard autonomous devices, buoys, various so-called ships-of-opportunity, and other platforms, in addition to the existing fleet of dedicated ocean exploration vessels. The Forum will help federal funding agencies and foundations define and prioritize exploration technology investment options for 2020-2030, and stimulate a vision among leading explorers of what it might be like to conduct expeditions in this time frame. James A. (Jamie) Austin Jr., University of Texas Robert Ballard, Ocean Exploration Trust and University of Rhode Island Frank Herr, Office of Naval Research, US Navy John Kreider, Oceaneering International Alan Leonardi, NOAA Ocean Exploration and Research Shirley Pomponi, Florida Atlantic University Rick Rikoski, Hadal Inc. Jerry Schubel, Aquarium of the Pacific Lance Towers, The Boeing Company Victoria Tschinkel, 1000 Friends of Florida Invitees represent the academic, government, non-profit, and for-profit communities, with expertise in both the engineering aspects of creating relevant equipment, and in exploratory and scientific applications of such equipment. Beyond the Ships: 2020-2025 is the first of four annual Marine Science & Policy Series conferences that will be organized by Rockefeller and Monmouth, with events taking place on alternating campuses in New York City and West Long Branch, New Jersey.


News Article | March 2, 2017
Site: www.eurekalert.org

The temperature of Earth's interior affects everything from the movement of tectonic plates to the formation of the planet. A new study led by Woods Hole Oceanographic Institution (WHOI) suggests the mantle--the mostly solid, rocky part of Earth's interior that lies between its super-heated core and its outer crustal layer -- may be hotter than previously believed. The new finding, published March 3 in the journal Science, could change how scientists think about many issues in Earth science including how ocean basins form. "At mid-ocean ridges, the tectonic plates that form the seafloor gradually spread apart," said the study's lead author Emily Sarafian, a graduate student in the MIT-WHOI Joint Program. "Rock from the upper mantle slowly rises to fill the void between the plates, melting as the pressure decreases, then cooling and re-solidifying to form new crust along the ocean bottom. We wanted to be able to model this process, so we needed to know the temperature at which rising mantle rock starts to melt." But determining that temperature isn't easy. Since it's not possible to measure the mantle's temperature directly, geologists have to estimate it through laboratory experiments that simulate the high pressures and temperatures inside the Earth. Water is a critical component of the equation: the more water (or hydrogen) in rock, the lower the temperature at which it will melt. The peridotite rock that makes up the upper mantle is known to contain a small amount of water. "But we don't know specifically how the addition of water changes this melting point," said Sarafian's advisor, WHOI geochemist Glenn Gaetani. "So there's still a lot of uncertainty." To figure out how the water content of mantle rock affects its melting point, Sarafian conducted a series of lab experiments using a piston-cylinder apparatus , a machine that uses electrical current, heavy metal plates, and stacks of pistons in order to magnify force to recreate the high temperatures and pressures found deep inside the Earth. Following standard experimental methodology, Sarafian created a synthetic mantle sample. She used a known, standardized mineral composition and dried it out in an oven to remove as much water as possible. Until now, in experiments like these, scientists studying the composition of rocks have had to assume their starting material was completely dry, because the mineral grains they're working with are too small to analyze for water. After running their experiments, they correct their experimentally determined melting point to account for the amount of water known to be in the mantle rock. "The problem is, the starting materials are powders, and they adsorb atmospheric water," Sarafian said. "So, whether you added water or not, there's water in your experiment." Sarafian took a different approach. She modified her starting sample by adding spheres of a mineral called olivine, which occurs naturally in the mantle. The spheres were still tiny--about 300 micrometers in diameter, or the size of fine sand grains--but they were large enough for Sarafian to analyze their water content using secondary ion mass spectrometry (SIMS). From there, she was able to calculate the water content of her entire starting sample. To her surprise, she found it contained approximately the same amount of water known to be in the mantle. Based on her results, Sarafian concluded that mantle melting had to be starting at a shallower depth under the seafloor than previously expected. To verify her results, Sarafian turned magnetotellurics -- a technique that analyzes the electrical conductivity of the crust and mantle under the seafloor. Molten rock conducts electricity much more than solid rock, and using magnetotelluric data, geophysicists can produce an image showing where melting is occurring in the mantle. But a magnetotelluric analysis published in Nature in 2013 by researchers at the Scripps Institution of Oceanography in San Diego showed that mantle rock was melting at a deeper depth under the sea floor than Sarafian's experimental data had suggested. At first, Sarafian's experimental results and the magnetotelluric observations seemed to conflict, but she knew both had to be correct. Reconciling the temperatures and pressures Sarafian measured in her experiments with the melting depth from the Scripps study led her to a startling conclusion: The oceanic upper mantle must be 60°C (~110°F) hotter than current estimates," Sarafian said. A 60-degree increase may not sound like a lot compared to a molten mantle temperature of more than 1,400°C. But Sarafian and Gaetani say the result is significant. For example, a hotter mantle would be more fluid, helping to explain the movement of rigid tectonic plates. Funding for this research was provided by the National Science Foundation and the WHOI Deep Ocean Exploration Institute. The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment. For more information, please visit http://www. .


News Article | April 12, 2016
Site: news.yahoo.com

Red crabs (Pleuroncodes planipes) gathered in the thousands in waters off the coast of Panama, captured on video in April 2015. A strange cloud of disturbed silt in the Pacific Ocean off the coast of Panama unexpectedly led marine biologists to an incredible sight: thousands of red crabs close to the sea bottom that were "swarming like insects," according to the researchers. The scientists were in a submersible investigating biodiversity at the Hannibal Bank seamount — an underwater mountain and a known ecological hotspot — when they spotted a disturbance in the water that led them to the unusual sight at depths of 1,165 feet to 1,263 feet (355 to 385 meters). A teeming mass of crabs seethed on the seamount's northwestern flank, with the highest density measured at 78 crabs in a single square meter (about seven crabs per square foot). [Video: Watch Swarms of Red Crabs on Hannibal Seamount] DNA analysis later identified the species as red crabs (Pleuroncodes planipes). These colorful swimming crustaceans are reddish orange and resemble miniature lobsters, with the adult carapace, or hard outer shell, measuring up to 1.3 inches (3.3 centimeters) in length. Red crabs are usually found in Baja California waters, off the northwest coast of Mexico. However, they can be abundant off the coasts of southern and central California during El Niño events, when western Pacific waters are warmer than average. But they had never been documented this far south, according to the study's lead author, Jesús Pineda, a biologist at Woods Hole Oceanographic Institution (WHOI) and chief scientist on the research cruise. "To find a species at the extreme of their range, and to be so abundant, is very unusual," Pineda said in a statement. Pineda suggested that the crabs, which are typically found in shallower waters, might have congregated at oxygen-poor depths to steer clear of predators. Scientists found and documented the swarming crabs in April 2015. Later in the year, a mass stranding of red crabs was reported on a San Diego beach, and genetic sampling confirmed that they were the same species as the crabs viewed at Hannibal Bank. This suggests that the species' usual range may extend farther south than previously suspected, the researchers reported in the study. While seamounts are known to host a high level of biodiversity, little is known about the processes shaping the wildlife populations that inhabit them. Unexpected sightings like this red crab swarm highlight how much there is yet to detect about how animals in these communities behave, and may inform future studies investigating interactions among species, researchers say. The findings were published online today (April 12) in the journal PeerJ. Follow Mindy Weisberger on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science. Copyright 2016 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


News Article | November 16, 2016
Site: www.sciencedaily.com

An acoustic buoy recently deployed by the Woods Hole Oceanographic Institution (WHOI) and WCS's (Wildlife Conservation Society) New York Aquarium is making its first near real-time detections of two rare great whale species in the New York Bight, including the highly endangered North Atlantic right whale. On November 14th, the hi-tech buoy named "Melville" detected the telltale "up call" of the North Atlantic right whale, one of the world's highly endangered whale species that numbers only 500 individual animals. It is the second detection of a North Atlantic right whale made by the buoy since October 26th. The acoustic buoy made another rare find on October 31st with the detection of a sei whale, a species that grows up to 65 feet in length and is rarely observed in New York waters. North Atlantic right whales are particularly vulnerable to getting hit by ships, so any information on the whereabouts of these animals along the coast is important. Researchers from WCS and WHOI report that the North Atlantic right whale detected on October 26th was outside of the New York Harbor Seasonal Management Area (SMA), one of a series of zones along the eastern seaboard established to protect the slow-swimming whales with boat speed restrictions during their migration periods. Vessel speed restrictions for the mid-Atlantic seasonal management areas -- including the SMA in New York Bight -- runs between November 1st and April 30th. "Having the ability to detect North Atlantic right whales and other species rarely seen in New York waters is extremely important given their endangered status," said Dr. Howard Rosenbaum of WCS's Ocean Giants Program and co-lead of the WCS New York Aquarium-WHOI project. "In particular, our ability to detect North Atlantic right whales in this area near the shipping lanes but outside these seasonal management areas will hopefully help with efforts to safeguard this highly endangered species in the New York Bight." "Ships are a significant hazard to whales in the New York region; the highest incidence of ship struck whales on the U.S. east coast occurs between the New York Bight and Chesapeake Bay. This new technology can help ships avoid lethal encounters with whales by alerting ship captains to the presence of the whales," said WHOI scientist Dr. Mark Baumgartner, developer of the whale detection software for the acoustic buoy and co-lead of the acoustic buoy project. The North Atlantic right whale grows up to nearly 60 feet in length and is called the "right" whale because the first commercial whalers deemed it the best species to hunt. Consequently, this coastal whale was nearly wiped out by whaling fleets before receiving international protection in the 1930s. Recent research indicates that, despite modest population growth during the 2000's, the species is now in decline and its existence remains threatened by ship strikes and entanglement in fishing gear. Sei whales are currently listed as "Endangered" on the IUCN's Red List and were also heavily exploited by commercial whaling fleets before becoming protected by federal and international laws. Little is known about this elusive giant, so any data on its presence in New York's coastal waters can help in management decisions. The WCS-New York Aquarium/WHOI research effort has now detected three whale species in New York Bight: the North Atlantic right whale, the sei whale, and the second largest animal on the planet, the fin whale. The acoustic buoy's most recent detection (made November 16th) was a fin whale, one of several detections of fin whales made since the buoy was deployed to its current location 22 miles south of Fire Island on July 23rd. Information about sounds detected by the buoy, including whale vocalizations, are transmitted by satellite to computers in Baumgartner's laboratory in Woods Hole, Massachusetts. The data are analyzed by Julianne Gurnee of the NOAA Northeast Fisheries Science Center, a partner in the buoy project, and posted on a public website as well as through WCS's New York Aquarium as part of its Blue York Campaign. The acoustic work by the WCS-New York Aquarium/WHOI complements previous acoustic research conducted by the Cornell's Bioacoustics Research Program, efforts by New York's Department of Environmental Conservation, along with collaborations with local NGOs such as the Coastal Research and Education Society of Long Island (CRESLI), Gotham Whale, and the Riverhead Foundation for Marine Research and Preservation. "WCS is known for working to save elephants, tigers, and other threatened species around the world," said Jon Forrest Dohlin, Vice President and Director of WCS's New York Aquarium. "We're also doing important science right here in New York Bight by learning more about the North Atlantic right whale, one of the most endangered whales on the earth."


News Article | November 3, 2016
Site: www.sciencedaily.com

Researchers have known for decades that whales create elaborate songs, sometimes projecting their calls for miles underwater. A new study from the Woods Hole Oceanographic Institution (WHOI), however, has revealed a previously unknown element of whale songs that could aid this mode of communication, and may play a pivotal role in locating other whales in open ocean. In a paper published in the November 2 issue of the online journal Biology Letters, WHOI biologist Aran Mooney describes approaching a group of humpback whales off the coast of the Hawaiian island of Maui. From aboard small research boat, he and his team measured two components of the whales' songs -- pressure waves (the type of sound wave that pushes on human eardrums, allowing us to hear), and particle motion (the physical vibration of a substance as sound moves through it). Surprisingly, he notes, particle motion in the water propagated much further than expected. "We threw our gear over the side, and let ourselves drift away from whales while measuring both particle motion and sound pressure. We didn't expect particle motion to be projected much at all -- just a few meters away at most. But as we got progressively further away, the particle motion stayed loud and clear," he says. The group measured only as far as 200 meters from the whales, but their data shows that this particle motion, especially in lower frequencies of sound, could travel much further than the distance recorded. "It's a whole other avenue of sound that we never knew whales could use," he notes. To envision the difference between these two modes of sound, Mooney says, imagine pulling up next to a car blasting loud music. "The stuff you hear is pressure waves; the stuff you feel vibrating your seat is particle motion," he adds. "When it comes to whale songs, particle motion hasn't really been studied much. It's a lot more complex to measure than pressure waves, so we don't have a great sense of how it propagates in water or air." Pressure waves are relatively simple to detect using specialized underwater microphone called a "hydrophone" -- a type of sensor that has been sold commercially for decades. Detecting particle motion, however, requires sensitive underwater accelerometers, which until recently have not been widely available to researchers. Mooney and his team, however, had both sensors on hand for an unrelated study in the area, allowing them to collect these unexpected recordings. Mooney is quick to note that his team didn't gather enough data to say definitively whether these whales could sense the particle motion present, but the anatomy of whale ear bones suggests that low-frequency vibration could be a major element of their hearing. Unlike dolphins and toothed whales, humpback whale ear bones are fused to the animals' skull, providing a direct link to any sort of vibration in the water column. "This could mean that their hearing is influenced by the way sound conducts through their bones," he says. "It raises the question: does a whale's lower jaw act like a tuning fork to direct vibrations to their ears? Previous papers have shown this bone conduction might be a viable mode of hearing." From an evolutionary standpoint, he adds, there's some precedence for this sort of vibratory hearing. Although most mammals sense sound via pressure waves in their eardrums, the closest living relative to whales -- hippopotamuses -- are known to sense sound underwater using their bodies, even while their ears remain above the surface. Elephants, another close relative to whales, can pick up ultra-low frequency vibrations through their feet, a trait that may help them locate their herd from miles away. Although Mooney's findings open the door for a range of evolutionary questions, he notes that it raises a much more immediate concern. If whales can in fact sense particle motion, similar vibrations caused by humans might interfere with the way the giant animals communicate. "Most human-made noise in the ocean low frequency, and the level of sound is doubling every decade. There's constantly more shipping, more seismic exploration for oil and gas," he says. Mining and construction, such as pile-driving machinery, is also increasing, contributing low-frequency particle motion that might propagate for miles underwater. "We humans don't hear well in water, so we overlook noise in the ocean, but it's very relevant cue for marine animals," Mooney adds. "This could be a major concern for whales."


News Article | November 17, 2016
Site: www.eurekalert.org

For decades, marine chemists have faced an elusive paradox. The surface waters of the world's oceans are supersaturated with the greenhouse gas methane, yet most species of microbes that can generate the gas can't survive in oxygen-rich surface waters. So where exactly does all the methane come from? This longstanding riddle, known as the "marine methane paradox," may have finally been cracked thanks to a new study from the Woods Hole Oceanographic Institution (WHOI). According to WHOI geochemist Dan Repeta, the answer may lie in the complex ways that bacteria break down dissolved organic matter, a cocktail of substances excreted into seawater by living organisms. In a paper released in the November 14, 2016 issue of the journal Nature Geoscience, Repeta and colleagues at the University of Hawaii found that much of the ocean's dissolved organic matter is made up of novel polysaccharides--long chains of sugar molecules created by photosynthetic bacteria in the upper ocean. Bacteria begin to slowly break these polysaccharides, tearing out pairs of carbon and phosphorus atoms (called C-P bonds) from their molecular structure. In the process, the microbes create methane, ethylene, and propylene gasses as byproducts. Most of the methane escapes back into the atmosphere. "All the pieces of this puzzle were there, but they were in different parts, with different people, in different labs, at different times," says Repeta. "This paper unifies a lot of those observations." Methane is a potent greenhouse gas, and it is important to understand the various sources of methane in the atmosphere. The research team's findings describe a totally new pathway for the microbial production of methane in the environment, that is very unlike all other known pathways. Leading up to this study, researchers like Repeta had long suspected that microbes were involved in creating methane in the ocean, but were unable to identify the exact ones responsible. "Initially, most researchers looked for microbes living in isolated low-oxygen environments, like the guts of fish or shrimp, but they pretty quickly realized that couldn't be a major factor. Too much oxygenated water flows through there," says Repeta. Many researchers also examined flocculent material--snowy-looking bits of animal excrement and other organic material floating in ocean waters. "Some of those also have low-oxygen conditions inside them," he says, "but ultimately they didn't turn out to be a major methane source either." In 2009, one of Repeta's co-authors, David Karl, found an important clue to the puzzle. In the lab, he added a manmade chemical called methylphosphonate, which is rich in C-P bonds, to samples of seawater. As he did, bacteria within the samples immediately started making methane, proving that they were able to take advantage of the C-P bonds provided by the chemical. Since methylphosphonate had never been detected in the ocean, Repeta and his team reasoned that bacteria in the wild must be finding another natural source of C-P bonds. Exactly what that source was, however, remained elusive. After analyzing samples of dissolved organic matter from surface waters in the northern Pacific, Repeta ran into a possible solution. The polysaccharides within it turned out to have C-P bonds identical to the ones found in methylphosphonate--and if bacteria could break down those molecules, they might be able to access the phosphorus contained within it. To confirm this idea, Repeta and his team incubated seawater bacteria under different conditions, adding nutrients such as glucose and nitrate to each batch. Nothing seemed to help the bacteria produce methane--until, that is, they added pure polysaccharides isolated from seawater. Once those were in the mix, the bacteria's activity spiked, and the vials began spitting out large amounts of methane. "That made us think it's a two-part system. You have one species that makes C-P bonds but can't use them, and another species that can use them but not make them," he says. Repeta and another co-author, Edward DeLong, a microbial oceanographer at the University of Hawaii, then began to explore how bacteria metabolize dissolved organic matter. Using a process called metagenomics, DeLong catalogued all the genes he could find in a sample of seawater from the north Pacific. In the process, he found genes responsible for breaking apart C-P bonds, which would allow bacteria to wrench phosphorus away from carbon atoms. Although DeLong was not certain which bacteria could actually do this, one thing was clear: If the gene was active, it would give an organism access to an important but rare nutrient in seawater. "The middle of the ocean is a nutrient-limited system," says Repeta. "To make DNA, RNA, and proteins, you need nitrogen and phosphorus, but in the open ocean, those nutrients are at such low concentrations that they're almost immeasurable." Instead of using free-floating nutrients in the water, Repeta says, DeLong's study showed that the microbes must somehow be able to crack into nitrogen and phosphorus hidden deep inside organic molecules. Although Repeta's latest paper confirms that it is indeed possible for bacteria to break apart C-P bonds, he notes that it's still not a particularly easy means of getting nutrients. With phosphorus tied up in organic molecules, it can be exceedingly difficult for bacteria to reach. If microbes can find other sources of the nutrient, he says, they will inevitably use those first. "Think of it like a buffet," Repeta says. "If you're a microbe, inorganic nutrients are like fruits and meats and all the tasty stuff that you reach for immediately. Organic nutrients are more like leftover liver. You don't really want to eat it, but if you're hungry enough, you will. It takes years for bacteria to get around to eating the organic phosphorus in the upper ocean. We don't exactly know why, but there's another really interesting story there if we can figure it out." Also collaborating on the study were Sara Ferrón and Oscar Sosa from the the University of Hawaii, Carl Johnson and Marianne Acker of the Woods Hole Oceanographic Institution, and Lucas Repeta of the University of California, Los Angeles. The research was supported by the Gordon and Betty Moore Foundation, the Simons Foundation and the National Science Foundation. The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment. For more information, please visit http://www. .


Turn on the faucet and it is likely that clean, drinkable water will come out; water that can be safely consumed. However, one in four cities around the world are water-stressed, and almost 97 percent of the Earth’s water is undrinkable. From the water crisis in Flint, Michigan, to droughts across the country, the significance of water utility and sustainability is more prevalent than ever before. To address the future of the water utilities, academics, entrepreneurs, business leaders, and thought leaders came together to discuss the future of water in the United States and around the world at the fifth annual MIT Water Summit on Nov. 17 and 18, hosted by the MIT Water Club. Members of the MIT Water Club moderated five panels over the two-day summit. This year’s topics ranged from the role of policy and economics on the future of water to the influence of industry and academic advances, but the overall vision was toward the future. “My aim was to hold an event with a broad enough appeal, but a specific focus explored through different approaches, such as technology, finance and policy,” said Gualtiero Jaeger, director of the MIT Water Summit and PhD candidate in the MIT- Woods Hole Oceanographic Institution (WHOI) Joint Program. “The theme ‘water utilities of the future’ gradually developed out of our initial ideas, and we looked for speakers with relevant expertise. Here our alumni and other connections helped us immensely.” “Creativity is part of the daily DNA of the water industry,” said keynote speaker George Hawkins, CEO and general manager of DC Water. Hawkins noted that many solutions to water problems require thinking outside the box, and cited the modernization and re-branding of DC Water to increase public awareness of their water utility. Similar creativity emerged through the interdisciplinary discussions at the MIT Water Summit. Luis Montestruque, president and CEO of EmNet, suggested the possible overlaps between green energy and water systems. Noting the use of solar energy to power electronic street signs, he questioned whether water utilities could follow to lower the energy costs. Stephen Estes-Smargiassi '79, director of planning and sustainability at Massachusetts Water Resources Authority (MWRA) and an alumnus of the MIT Department of Civil and Environmental Engineering (CEE), served as a keynote speaker and gave the Massachusetts perspective of water and energy. In his talk, Estes-Smargiassi highlighted the significance of water as an energy source, pointing out that 31 percent of the energy needed by MWRA is renewable energy, meaning the amount of money spent purchasing energy and power has decreased. By recycling water, Massachusetts is simultaneously creating energy. Ed McCormick, president of McCormick Strategic Water Management, cited potable reuse as one major example of creativity in the water sector during the panel on the role of economics. Potable reuse is the use of technologies to treat wastewater without putting water back into the environment and through the water cycle. McCormick acknowledged the negative perceptions people have of associating human waste with drinking water. “We replicate the water cycle with technology; we can do as good a job as nature. Those negative perceptions are changing and that’s where I see the creativity coming big time. It hasn’t quite swept to areas where you have more water than you need, but it’s certainly happening in the Southwest,” he said. Professor Gabriella Carolini of the MIT Department of Urban Studies and Planning suggested that there is no shortage of technological innovation, but that technological implementation is the major issue in the water sector. “Implementation is a problem that is not just financial, regulatory, technological or social; it’s a combination of all of those things, so we need to look at the implementation issue,” she said. Current policies and regulations are also not always conducive to rapid execution of news ideas. One component to this issue is the extensive pilot period, when technologies and ideas are studied before used widely. “We pilot for so long that by the time you actually determine that something is effective, there’s a new technology that we want to pilot. What we want to do is release some of the regulations a little bit so that we can promote some of these innovative technologies that are out there” said Mary Barry, executive director of New England Water Environment Association (NEWEA). Instead of hindering creative ideas with regulations and pilot programs, “We should be promoting innovation. That’s the only way we are going to grow and the only way we’re going to make things more efficient, both on the energy side and on the financial side,” she said. The creation of innovative technologies and their aligning with regulatory standards are only worth so much until the general public is on board with their implementation. As Ed McCormick suggested, changing the public’s perception of an issue of new innovative solutions is critical to the success of the product and the water sector. Communicating with the public to implement new ideas and technologies Speakers noted that reaching the general public is a difficult task, especially with the wide variety of media outlets and fragmented audiences. “I think the media can be a great asset to us as an industry, I just don’t think water is their focus,” said Mary Barry of NEWEA. One way to reach adults is through their children, who often talk about what they learn with their parents at home, she highlighted, citing the effectiveness of marketing to children. “Talking to students in schools allows them to go home and talk with their parents about something their parents might not be thinking about, because it has always been a luxury for them to have clean water and sanitation,” Barry said. The media is still considered a valuable method, however: “The full spectrum of media is an extremely useful tool, for even controlling outstanding systems like our own. I would say that the situation in Flint is an experience that is super important. It’s one thing to say that we have achieved amazing results in drinking water in this country, but I might suggest that we are only as good as our weakest link, and if something like that can happen in Flint, then it can happen anyplace,” said Carolini. Communication takes many forms beyond the media as well, such as through access to data. The availability and transparency of data in the water sector was a theme that continued throughout the Water Summit. During the panel “Visions for the Future,” panelists discussed the presence of smart systems, and the observation of resulting consumer behavior changes. Professor James Wescoat of the Department of Architecture and the MIT Tata Center spoke of staying in a hotel in Europe that displayed water meters in each room and showed how much water was used when a visitor turned on the shower or the sink. He recalled hearing fellow travelers discuss how few liters of water they used, each wanting to be lower than his counterpart. On that note, George Hawkins pointed out that when DC Water installed automatic meter readings in 2002, they noticed drops in water use. DC Water noted similar decreases when they began sending high-use notification alerts to customers, courtesy messages notifying customers of significant changes in water use, which could indicate leaking pipes. Alexander Heil, chief economist of the Port Authority of New York and New Jersey, made a similar point about water usage during the panel on the role of economics, noting that without smart systems and up-to-date information of one’s water usage, there is a disconnect between how people pay for water and how they use it. “There is a discrepancy between the point of usage and the point of payment. For example, if you have a quarterly billing cycle, nobody remembers how they used water three months ago.” The availability of data at water utility plants is crucial for the plants to troubleshoot any issues with their product. Anupam Bhargava, vice president of advanced technology and innovation at Xylem Inc., discussed this importance through disruptive sensing capabilities, one of the areas Xylam is looking into for the future. Disruptive sensing capabilities would allow water utility plants to detect issues immediately and allow them to be proactive in finding a solution. Noting that water, unlike other products commonly sold, cannot be recalled once it leaves the plant, Bhargava said that “real-time sensing capability is going to allow our customers to operate and manage their plants a lot more productively and safely.” Disruptive sensing capabilities would thus allow water utility plants to have important information at their fingertips and to avoid major public health hazards. Collaborating to solve major issues in the water sector Collaboration is often seen in the water sector to address major issues and find solutions. However, collaboration does not always mean centralized ownership. George Hawkins of DC Water mentioned the challenges of creating a centralized water system, because smaller municipalities prefer to maintain ownership of localized water sources. Instead, he proposed the creation of a more coordinated system on a broader scale, rather than centralized ownership. Ed McCormick shared that he has started to see such coordination through regional partnerships between smaller utilities. “In the San Francisco Bay Area, there are nearly 60 utilities that all discharge in the San Francisco Bay, some of them are very small and others are very large. What we have seen are agreements where small utilities can connect with other utilities to purchase bulk chemicals and get the benefit of scale, that larger utilities can get,” McCormick said. Marcus Gay, executive director of New England Water Innovation Network, pointed out that “innovation isn’t just about new technological solutions, it’s about bringing both innovative technological solutions and market adoption together. It’s an entire process.” One way to do this is to foster collaboration between academia and the water industry markets, to create a well-researched product or plan to implement and have a real-world impact. This was brought to life by the Water Summit’s panel on “Academia to Markets.” John Lienhard V, professor in the MIT Department of Mechanical Engineering and director of the Abdul Latif Jameel World Water and Food Security Lab, noted that the best partnerships are with people who understand the need for water. “We have worked with a number of international institutions from countries that have serious water challenges. We have tried to get into these issues with them because they understand that these are not simply academic problems, but they are problems that can be translated back into the needs of their countries and societies in a way that provides water to people’s taps, that help people actually live and survive. In those cases, we have seen that the research is productive, it is viewed as important, it is supported well and it has the impact we need in both the practical and academic side,” he said. The fifth annual Water Summit was a full house, complete with academics from MIT and neighboring schools, business leaders, thought leaders, and students. Sami Harper, a graduate student in CEE, attended the summit to find out more about how changing technology is affecting the way we get our water. “I learned a lot from the keynote addresses which shed some light on water utility operations and the future of the industry,” she said. Members of the MIT Water Club also benefited from the event. “The interactions with professionals beyond our academic research was immensely valuable. We received insight into the water industry and the workings of institutions and companies in the water world,” Gualtiero Jaeger said. Sponsors for this year's Water Summit included Desalitech, Gradient Corporation, Abdul Latif Jameel World Water and Food Security Lab, the MIT Department of Civil and Environmental Engineering, Massachusetts Clean Energy Center, New England Water Innovation Network, Pepsico, Woods Hole Oceanographic Institution, and Xylem.


News Article | April 12, 2016
Site: www.techtimes.com

Thousands of crabs are gathering off the coast of Panama, an event which is resembling an alien invasion, according to researchers. This occurrence is a surprise to researchers who have studied the animals. Red crabs are massing on the Hannibal Bank Seamount, located in the waters near Panama. The animals are gathering in oxygen-poor water just above the seafloor, around 1,200 feet beneath the surface of the water. Researchers aboard the Deep Rover 2 submersible, taking part in the last dive of a month-long investigation, recorded the unexpected encounter in April 2015. The team noticed the water was becoming murkier as they dove to greater depths. "There was this turbid layer, and you couldn't see a thing beyond it. We just saw this cloud but had no idea what was causing it. As we slowly moved down to the bottom of the seafloor, all of the sudden we saw these things. At first, we thought they were biogenic rocks or structures. Once we saw them moving--swarming like insects--we couldn't believe it," Jesus Pineda, a biologist at WHOI, said. Pleuroncodes planipes, also known as tuna crabs, are often found in waters off Baja California and the Gulf of California. They are not normally found as far south as Panama, and finding a large gathering of the creatures was especially surprising to investigators. This event marks the furthest south the animals have ever been seen. The tuna crab, which are a favorite food of the large fish for which they are named, may have moved to the low-oxygen water as a means to avoid predators, which also includes marine mammals. Seamounts like the site of the gathering are under water mountainous regions, rich with a wide variety of life forms. The study which found the underwater meeting of crabs was aimed at discovering why the Hannibal Seamount is able to sustain such a wide range of plants and animals. A large group of red crabs washed onto the beaches of southern California just months after the unusual gathering near Panama was recorded. Biologists believe this event was driven by warming water, heated by El Nino. Analysis of the unisual gathering of tuna crabs was presented in the journal PeerJ. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | September 28, 2016
Site: news.mit.edu

In certain parts of the ocean, towering, slow-motion rollercoasters called internal tides trundle along for miles, rising and falling for hundreds of feet in the ocean’s interior while making barely a ripple at the surface. These giant, hidden swells are responsible for alternately drawing warm surface waters down to the deep ocean and pulling marine nutrients up from the abyss. Internal tides are generated in part by differences in water density, and created along continental shelf breaks, where a shallow seafloor suddenly drops off like a cliff, creating a setting where lighter water meets denser seas. In such regions, tides on the surface produce oscillating, vertical currents, which in turn generate waves below the surface, at the interface between warmer, shallow water, and colder, deeper water. These subsurface waves are called “internal tides,” as they are “internal” to the ocean and travel at the same frequency as surface tides. Internal tides are largely calm in some regions but can become chaotic near shelf breaks, where scientists have been unable to predict their paths. Now for the first time, ocean engineers and scientists from MIT, the University of Minnesota at Duluth (UMD), and the Woods Hole Oceanographic Institution (WHOI) have accurately simulated the motion of internal tides along a shelf break called the Middle Atlantic Bight — a region off the coast of the eastern U.S. that stretches from Cape Cod in Massachusetts to Cape Hatteras in North Carolina. They found that the tides’ chaotic patterns there could be explained by two oceanic “structures”: the ocean front at the shelf break itself, and the Gulf Stream — a powerful Atlantic current that flows some 250 miles south of the shelf break. From the simulations, the team observed that both the shelf break and the Gulf Stream can act as massive oceanic walls, between which internal tides ricochet at angles and speeds that the scientists can now predict. The researchers have published their findings in the Journal of Geophysical Research: Oceans and the Journal of Physical Oceanography. The team includes Samuel Kelly, an assistant professor at UMD who was a postdoc at MIT for this research; Pierre Lermusiaux, an associate professor of mechanical engineering and ocean science and engineering at MIT; Tim Duda, a senior scientist at WHOI; and Patrick Haley, a research scientist at MIT. Lermusiaux says the team’s simulations of internal tides could help to improve sonar communications and predict ecosystems and fishery populations, as well as protect offshore oil rigs and provide a better understanding of the ocean’s role in a changing climate. “Internal tides are a big chunk of energy that’s input to the ocean’s interior from the common [surface] tides,” he explains. “If you know how that energy is dissipated and where it goes, you can provide better predictions and better understand the ocean and climate in general.” The effects of internal waves were first reported in the late 1800s, when Norwegian sailors, attempting to navigate a fjord, experienced a strange phenomenon: Even though the water’s surface appeared calm, their ship seemed to strongly resist sailing forward — a phenomenon later dubbed “dead water.” “It would be dead calm in the water, and you’d turn your ship on but it wouldn’t move,” Lermusiaux says. “Why? Because the ship is generating internal waves because of the density difference between the light water on top and the salty water on the bottom in the fjord, that keep you in place.” Since then, scientists have found that surface tides, just like internal tides, are generated by the cyclical, gravitational pull of the sun and the moon, and travel between density-varying mediums. Surface waves travel at the boundary between the ocean and the air, while internal waves and internal tides flow between water layers of varying density. “What people didn’t really know was, why can those internal tides be so variable and intermittent?” Duda says. In the summer of 2006, oceanographers embarked on a large-scale scientific cruise, named “Shallow Water ’06,” to generate a detailed picture of how sound waves travel through complex coastal waters, specifically along part of the Middle Atlantic Bight region. The experiment confirmed that internal tides stemmed from the region’s shelf break at predictable intervals. Puzzlingly, the experiment also showed that internal tides arrived back at the shelf break at unpredictable times and locations. “One would think if they were all generated at the shelf break, they would be more or less uniform, in and out,” Lermusiaux says. To solve this puzzle, Lermusiaux, Haley, and their colleagues incorporated data from the 2006 cruise into hydrodynamic simulations to represent tides in a realistic ocean environment. These data-driven simulations included not only tides but also “background structures,” such as density gradients, eddies, and currents such as the Gulf Stream, with which tides might interact. After completing more than 2,500 simulations of the Middle Atlantic Bight region, they observed that internal tides generated close to the shelf break seemed to flow out toward the ocean, only to bounce back once they reached the Gulf Stream. As the Gulf Stream meandered, the exact direction and location of the internal tides became more variable. "Looking at the initial plots from the simulations, it was obvious that some type of interaction was happening between the internal tide and Gulf Stream,” Kelly says. “But the simulations could produce a huge number of complicated interactions and there are lots of theories for different types of interactions. So we started testing different theories.” The researchers sought to find mathematical equations that would describe the underlying fluid dynamics that they observed in their simulations. To do this, they started with an existing equation that characterizes the behavior of internal tides but involves an idealized scenario, with limited interactions with other features. The team added new “interaction terms,” or factors, into the equations that described the dynamics of the Gulf Stream and the shelf break front, which they derived from their data-driven simulations. “It was really exciting when we wrote down a set of slightly idealized equations and saw that the internal tides extracted from the complex simulations were obeying almost the exact same equations," Kelly says. The match between their simulations and equations indicated to the researchers that the Gulf Stream and the shelf break front were indeed influencing the behavior of the internal tides. With this knowledge, they were able to accurately predict the speed and arrival times of internal waves at the shelf break, by first predicting the strength and position of the Gulf Stream over time. They also showed that the strength of the shelf break front alters the speed and arrival times of internal tides. The team is currently applying their simulations to oceanic regions around Martha’s Vineyard, the Pacific Islands, and Australia, where internal tides are highly variable and their behavior can have a large role in shaping marine ecosystems and mediating the effects of climate change. “Our work shows that, with data-driven simulations, you can find and add missing terms, and really explain the ocean’s interactions,” Lermusiaux says. “If you look at ocean or atmospheric sciences today, understanding interactions of features is where big questions are.” This research was funded in part by the Office of Naval Research and the National Science Foundation.

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