The China Earthquake Administration , is mandated by the Law of the People's Republic of China on Protecting Against and Mitigating Earthquake Disasters of PRC to enforce the earthquake administration in the nation under the administration of State Council of the People's Republic of China.Some English text use the name Chinese Seismic Bureau . In older text, it was also referred to by its former name, National Earthquake Bureau or National Seismic Bureau . Wikipedia.
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 203.66K | Year: 2016
Our overall aim is to build earthquake resilience in China by improving (a) the assessment of seismic hazard and risk from earthquakes and consequent events and (b) the communication and use of probabilistic information in the development of more proportionate and risk-based strategies for disaster risk reduction. We will build on and extend a recently-developed historical catalogue for earthquakes, extend it for the first time to include consequent events (landslides, debris/mud-flows, outburst floods), unify this new database with modern instrumental data, use state-of the art statistical techniques to quantify the associated uncertainties, and incorporate social science-based understanding of risk communication and governance to improve policy development and implementation. The work programme will be carried out in Si-chuan (including the 2008 Wenchuan earthquake) and Yun-nan provinces. While they are both tectonically active, and mountainous, and thus vulnerable not only to earthquakes but also to consequent hazards of earthquake-triggered landslides and flooding, Si-chuan is one of the wealthiest provinces in China, while Yun-nan is one of poorest. These differences in wealth, combined with the recency of the devastating 2008 Wenchuan in Si-chuan compared to the more attenuated memory of the 1996 Lijiang earthquake in Yun-nan, make for a natural experiment in which to test the efficacy of improved probabilistic assessment of risk and associated uncertainty to people and property by earthquakes, and consequent event hazards, in supporting more risk-based approaches to disaster reduction. This project will promote long-term sustainable growth in earthquake prone regions of China by improving both the assessment of earthquake hazard and consequent event risk and the communication, understanding, and use of the resulting probabilistic forecasts for disaster risk reduction by policymakers and local publics. It addresses several specific capacity gaps identified in successive Chinese national disaster risk reduction strategies. As well as engaging with policymakers at both the national and local levels to improve the effectiveness of emergency planning and building code regulation, we will also engage directly with local publics to enhance public understanding of risk and capacity to deal with it. In so doing, the project will also fulfil the UKs Official Development Assistance (ODA) commitment to promoting the economic development and welfare of developing countries by drawing on UKs science base to address a key vulnerability differentially affecting the very poorest in China.
News Article | April 20, 2016
A rare collaboration between North Korean and Western scientists has probed the ground beneath a dangerous volcano on the Chinese–Korean border. The work illuminates the geological plumbing that could underlie possible future eruptions. “Now we can start to see into the underbelly of the volcano,” says Kayla Iacovino, a volcanologist with the US Geological Survey in Menlo Park, California. She and her colleagues, led by Ri Kyong-Song of the Earthquake Administration in Pyongyang, Democratic People’s Republic of Korea (DPRK), used seismic data to pinpoint molten rock beneath the mountain. The paper appears on 15 April in Science Advances1. Called Mount Paektu on the Korean side and Changbaishan on the Chinese side, the volcano is considered one of the region’s most hazardous. Around the year 946, it let loose one of the most powerful eruptions in recorded history, showering ash as far away as Japan. Today, more than 1.6 million people live within 100 kilometres of Paektu. “This volcano is quiet at the moment, but it’s definitely got potential,” says team member James Hammond, a seismologist at Birkbeck, University of London. “We need to keep an eye on it.” Lava could potentially erupt as much as 20 kilometres away from the mountain’s summit, says Haiquan Wei, a volcanologist at the China Earthquake Administration in Beijing who has studied the mountain’s past activity2. Because the volcano straddles the Chinese–North Korean border, scientific studies have been fragmented between the two countries. “People have spent their whole lives studying the volcano and have never seen it from the other side,” says Iacovino. The mountain holds a special significance in Korea as the purported birthplace of both the founder of the first Korean kingdom and of former DPRK leader Kim Jong-Il. Paektu last erupted in 1903. In 2002 it began shaking with thousands of tiny earthquakes, possibly as magma shifted underground. The seismic unrest ended after several years without any lava erupting — but the episode prompted researchers on both sides of the border to reassess what they knew about the volcano and to try to prepare for what it might unleash in the future. In 2011, at the invitation of the DPRK government, Hammond went to North Korea with Clive Oppenheimer, a volcanologist at the University of Cambridge, UK. That meeting spawned an unprecedented collaboration to try to understand Paektu better from the Korean side3. With diplomatic support from the American Association for the Advancement of Science in Washington DC and the Royal Society in London, Hammond arranged to bring six state-of-the-art seismometers into North Korea. It wasn’t easy. It took years to sort out the proper import licences, and the team had to ditch plans to measure conductivity beneath the volcano because the required equipment has a second use in submarine detection. But in the end, Hammond and his colleagues deployed the seismometers in a 60-kilometre-long line east from Paektu’s summit, deep into the countryside. “Every year I would visit these families and they would look after our stations for us,” says Hammond. “They clearly wanted to understand this volcano.” The seismometers remained in place from August 2013 to August 2015 (which meant that they were not present during any of the DPRK’s four nuclear-weapons tests). By analysing how seismic waves travelled beneath the volcano, the scientists found that a significant part of the crust must be at least partially molten. “Whether or not that melt is going to turn into an eruption is a bigger question,” says Iacovino. “But at least we can now start to draw a picture of what’s happening.” Other studies have hinted at the presence of molten rock beneath the volcano before, says Haibo Zou, a geoscientist at Auburn University in Alabama. But “any new serious research,” he says, ”is of interest”. Chinese and North Korean scientists monitor Paektu using their own seismic networks as well as gas samples collected from hot springs. But until geologists have a better understanding of what the volcano has done in the past, it will be hard to tell emergency officials how they should prepare for future eruptions, says Iacovino. For instance, she has been mapping the geology of the ash, pumice and other rocks thrown outward in the AD 946 eruption. Enormous clouds of superheated gas and ash swept downhill, followed by destructive mudslides. If Paektu were to erupt again, it might send water rushing downhill from the summit lake, or clouds of ash skyward to interfere with aeroplane flights across Korea and Japan. By studying rocks collected during a 2013 visit, Iacovino has found that the AD 946 eruption probably spewed much more sulfur dioxide into the atmosphere than earlier studies reported4. That suggests that Paektu has the potential to alter global climate. Hammond will be in Pyongyang next week, working on future proposals to expand studies of Paektu. “We’d really like to work together with the Chinese and North Koreans to study the volcano as a whole volcano, using instruments on both sides of the border,” he says. “Ultimately, it’s up to them to work together, and maybe we can be a part of it.”
News Article | April 18, 2016
In an attempt to understand the dynamics of a sleeping, yet dangerous volcano, reclusive North Korea finally opens its doors to Western scientists. North Korean scientists collaborated with Western experts in examining the underground of Mt. Paektu that lies on the Chinese-Korean border. It is also known as Changbaishan on the Chinese side. The study highlighted the geological makeup of the volcano's underbelly that allowed scientists to gather useful data, which can be used in possible eruptions in the future. Kayla Iacovino of U.S. Geological Survey in Menlo Park, California, together with Ri Kyong-Song of the Earthquake Administration in Pyongyang, Democratic People's Republic of Korea (DPRK) used previous seismic information to locate the molten rock underneath the sleeping mountain. The volcano is described as one of the most hazardous in North Korea. Mount Paektu's most powerful eruption that dates back to the year 946, spewed ash that reached Japan. Based on previous activities of the volcano, its eruption can reach 20 kilometers (12 miles) away from its summit, said Haiquan Wei, a resident volcanologist at China Earthquake Administration. "The volcano is quiet at the moment, but it's definitely got potential," said seismologist James Hammond of Birkbeck, University of London. "We need to keep an eye on it." At present, more than 1.6 million residents are within 100 kilometers (62 miles) of the volcano. Mount Paektu's last eruption was in 1903. In 2002, the volcano showed seismic activity, which are thought to cause magma to shift underground. Even though the shaking eventually stopped after several years without any untoward incidents, researchers knew that they needed to do something to prepare for eruptions. Six state-of-the-art seismometers were placed in the volcano from August 2013 to August 2015 to analyze seismic waves and how it travels under the volcano. Researchers found that part of the crust was partially molten. "Whether or not that melt is going to turn into an eruption is a bigger question," Iacovino said. "But at least we can now start to draw a picture of what's happening." Iacovino said helping emergency officials in preparing for a possible eruption is still difficult at this time because they need to fully understand its past activities. Iacovino added that if Mount Paektu erupts again, it could send clouds of ash skyward or send water to rush downhill from the summit lake. The scientists believe that the collaboration would allow more insight into the volcano's activities and potential for eruption. Since it is straddling two countries, previous knowledge about the volcano is fragmented. Iacovino said that those studying it from one side have no idea of what is on the other side. With diplomatic support from the American Association for the Advancement of Science in Washington DC and the Royal Society in London, Hammond began the study in North Korea. The scientists express gratitude that they were given the chance to study the volcano, which is significant to Korea as it is the highest point in the country and is believed to be the birthplace of both the founder of first Korean kingdom and former DPRK leader Kim Jong-Il. Hammond is currently working on proposals to further the study. He said that the Chinese and North Koreans can work together, but hopes to be part of it still. "We'd really like to work with together with the Chinese and North Koreans to study that volcano as a whole volcano, using instruments on both sides of the border." Studying eruption potential of volcanoes is important in understanding and preparing for disasters. Earth is presently in a period of extreme volcanic activity, said scientists from the European Science Foundation (ESF). Supervolcanoes, like the one in Yellowstone National Park, can erupt and cause global calamity. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.
Zhang L.,China Earthquake Administration |
He C.,China Earthquake Administration
Tectonophysics | Year: 2013
We investigated the properties of frictional sliding of natural gouges collected from Longmenshan fault zone which ruptured during the Wenchuan Mw7.9 earthquake. Based on XRD analysis, five gouge samples of different mineralogical assemblies and mineral contents are chosen for frictional sliding experiments with initial confining pressure of 50. MPa and at different temperatures from 25. °C to 150. °C. To obtain the rate dependence of friction, shearing rates are stepped up and down in the range of 0.0488 to 6.1. μm/s. While the friction coefficient of most gouge samples decreases with the clay content following a general trend consistent with previous studies, the organic-matter-bearing sample (PX-3) shows a much lower value than the prediction by the general trend, indicating further strength reduction due to the ~ 9% organic matter included. We also found a significant effect of temperature on the sliding behavior of organic-matter-bearing and carbonate-rich gouges. When temperature increases to 150. °C, the PX-3 sample (with organic matter) exhibits unstable oscillation that indicates velocity-weakening frictional sliding behavior, in contrast to the velocity-strengthening behavior at lower temperatures. The velocity dependence of carbonate-rich samples (PX-1, PX-2) with more than 50. wt.% carbonates is also sensitive to temperature and shearing rates, and both samples have smaller velocity dependence of friction (a-b) at higher temperatures. The (a-. b) value of the PX-2 sample (with ~ 80% carbonates) even decreases to the velocity neutral point at 150. °C and slow shearing rates. Based on the rate and state friction framework, fast slip nucleation is possible for faults associated with the organic-matter-bearing gouge at 150. °C, whereas triggered seismic slips are possible in faults that include the carbonate-rich samples which have a small (a-b) value at 150. °C. The temperature-dependent sliding behavior of carbonate-dominant and organic-matter-bearing gouges probably provides a new clue to the problem of transition from shallow aseismic zone to seismic zone in subduction interfaces of the oceanic plate. © 2013 Elsevier B.V.
Zhang P.-Z.,China Earthquake Administration
Tectonophysics | Year: 2013
One of remarkable geological and geomorphological features in continental China is the presence of a north-south trending tectonic zone which separates the seismically active Tibetan Plateau to the west from the tectonically stable South China and Ordos blocks to the east. The zone also owns a name of "north-south seismic belt" as a large number of great historical earthquakes occur on it. The most recent one, the 2008 Wenchuan earthquake, attests its recent tectonic activity. In this review I take the Western Sichuan region as an example to probe the structural styles and kinematic pattern as well as deep geological process associated with tectonic deformation of the north-south trending zone. Through integrated studies on active faults, GPS crustal deformation, and geophysical structure, we show that deformation in the Western Sichuan is governed by interactions among three crustal blocks (Songpan, Chuandian, and South China) of distinctive rheological properties under the tectonic framework that eastward growth of the "soft" Eastern Tibet is blocked by the "hard" lithosphere of the South China block. The left-lateral Xianshuihe Fault continues to the north-south trending fault system without crustal shortening to form a bounding fault to limit the northern extend of the magnificent clockwise rotation of crustal material around the Eastern Himalaya Syntax. Upper crust of the three blocks is dominated by brittle deformation, whereas the ductile flow of lower crust would drag the brittle upper crustal blocks to move with respect to each other. The relative motions among the brittle upper crustal blocks cause strain accumulations among their bounding faults to generate large earthquakes. Deformation of the Western Sichuan region can thus be described in terms of combined model of rigid block movement and continuous deformation. We suggest this combined model can be applied to entire continental China. © 2012 .
Lei J.,China Earthquake Administration
Journal of Geophysical Research: Solid Earth | Year: 2011
Detailed 3-D tomographic images of P and S wave velocity (Vp, Vs) and Poisson's ratio (σ) under the central and western Tien Shan orogenic belt are determined by using a large number of high-quality P and S wave arrival times from local earthquakes. The results show that under the Tien Shan orogenic belt high-Vp, high-Vs, and low-σ anomalies are revealed in the upper and middle crust, possibly indicating the existence of the Paleozoic crystalline basement rocks, while low-Vp, low-Vs, and high-σ anomalies appear in the lower crust and upper mantle, perhaps suggesting that the hot and wet material is upwelling under the Tien Shan orogenic belt from the mantle. Some high-Vp, high-Vs, and low-σ anomalies are tilted toward the Tien Shan along with the seismicity. These are found in the collision zones between the Tien Shan and the Tarim basin in the south and the Kazakh shield in the north and suggest the underthrusting of the Tarim and Kazakh lithosphere beneath the Tien Shan. Meanwhile, some low-Vp, low-Vs, and high-σ anomalies are imaged in other parts of these collision zones, perhaps indicating the intrusion of the hot and wet material into the crust from the upper mantle. These results indicate that both the upwelling of the hot and wet material and the underthrusting of the Tarim and Kazakh lithosphere may have played an important role in the mountain building. Under the Tarim and Fergana basins, low-Vp, low-Vs, and high-σ anomalies are revealed in the upper crust, while high-Vp, high-Vs, and low-σ anomalies are visible in the lower crust and upper mantle. These may reflect the existence of less compacted sedimentary material in the shallow crust and more highly compacted craton-like structures in the deeper crust and upper mantle under the basins. The Talas-Fergana fault shows an obvious tectonic boundary between central and western Tien Shan. The central Tien Shan displays high-Vp, high-Vs, and low- anomalies in the upper and middle crust, while western Tien Shan exhibits low-Vp, low-Vs, and high-σ anomalies. However, the pattern of seismic structure between central and western Tien Shan reverses in the lower crust. Such a correlation may extend down to the upper mantle, suggesting that the Talas-Fergana fault may be a lithospheric-scale boundary. Additionally, a columnar low-Vp and low-Vs anomaly is clearly observed around the turning point of the Talas-Fergana fault from the NWN to NWW trending orientations and may indicate that the fault provides a channel for the hot and wet material upwelling from the mantle to the surface. Copyright 2011 by the American Geophysical Union.
Lei J.,China Earthquake Administration
Journal of Geophysical Research: Solid Earth | Year: 2012
A high-resolution tomographic model of the upper mantle beneath the North China Craton (NCC) is determined using a large number of precisely hand-picked teleseismic P wave arrival times. The results are generally consistent with previous results but high-quality arrivals provide new insights into the dynamics beneath the NCC. Obviously north-south trending low-velocity (low-V) zones are revealed down to ∼300-400 km depth under the Shanxi rift and Tanlu fault zone, while a north-south trending high-velocity (high-V) zone representing the remainder of detached lithosphere is visible down to ∼200 km depth under the western portion of eastern NCC. High-V anomalies representing the detached lithosphere are detected at 200-400 km depth under central and eastern NCC. Under the Ordos block high-V anomalies are visible above ∼400 km depth, indicating intact lithosphere. Broad high-V anomalies representing the stagnant Pacific slab are imaged with a low-V anomaly from Datong volcano to the edge of Bohai Sea in the mantle transition zone beneath eastern and central NCC, suggesting that the Pacific slab has subducted to central NCC but with a gap. A continuously Y-shaped low-V structure is clearly imaged under Datong volcano and Bohai Sea from the lower mantle through this gap in the mantle transition zone to the upper mantle, indicating the existence of a lower mantle plume. These results suggest that in addition to the subduction of the Pacific plate, the plume has also played an important role in lithospheric destruction by thermal erosion of the asthenosphere and detachment of the lithosphere beneath the NCC. © 2012 American Geophysical Union. All Rights Reserved.
Xu C.,China Earthquake Administration
Geoscience Frontiers | Year: 2015
Inventory maps of earthquake-triggered landslides can be constructed using several methods, which are often subject to obvious differences due to lack of commonly accepted criteria or principles. To solve this problem, the author describes the principles for preparing inventory maps of earthquake-triggered landslides, focusing on varied methods and their criteria. The principles include the following key points: all landslides should be mapped as long as they can be recognized from images; both the boundary and source area position of landslides should be mapped; spatial distribution pattern of earthquake-triggered landslides should be continuous; complex landslides should be divided into distinct groups; three types of errors such as precision of the location and boundary of landslides, false positive errors, and false negative errors of earthquake-triggered landslide inventories should be controlled and reduced; and inventories of co-seismic landslides should be constructed by the visual interpretation method rather than automatic extraction of satellite images or/and aerial photographs. In addition, selection of remote sensing images and creation of landslides attribute database are also discussed in this paper. Then the author applies these principles to produce inventory maps of four events: the 12 May 2008 Wenchuan, China Mw 7.9, 14 April 2010 Yushu, China Mw 6.9, 12 January 2010 Haiti Mw 7.0, and 2007 Aysén Fjord, Chile Mw 6.2. The results show obvious differences in comparison with previous studies by other researchers, which again attest to the necessity of establishment of unified principles for preparation of inventory maps of earthquake-triggered landslides. © 2015 China University of Geosciences (Beijing) and Peking University.
Xu C.,China Earthquake Administration
Geomorphology | Year: 2014
Gorum et al. (2013, Geomorphology 184, 127-138) carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 Mw 7.0 Haiti earthquake. They revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography. They also suggested that blind-rupture earthquakes trigger fewer landslides than surface-rupture earthquakes on thrust reverse faults. Although a few lines of evidence indicate that buried-rupture earthquakes might trigger fewer landslides than surface-rupture earthquakes on reverse faults, more careful comparisons and analyses indicate that it is not always true. Instead, some cases show that a buried-rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area, whereas surface-rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area. © 2014 Elsevier B.V.
Du X.B.,China Earthquake Administration
Science China Earth Sciences | Year: 2011
Two types of changes in apparent resistivity (AR) have been linked to earthquake occurrences. This paper studies the changes and their causes, in detail with the ultimate purpose of developing and assessing a method of earthquake (EQ) prediction. The AR changes of the first type (CFT) are considered to be precursors related to earthquakes (EQs); these appear mostly in the medium-term period before EQs and in the short-term period preceding EQs. The changes of the second type (CST) are characterized by a turning anomaly of a long-trend AR variation or the drastically descending/ascending anomaly superimposed on such a variation; these appear synchronously in large areas, such as the Chinese mainland, and northern and northwestern China, ect. Their spatio-temporal clusters correspond well to high seismicities in the areas and distant great EQs around the Chinese mainland. Based on the behaviors of the two types of changes, the AR changes observed prior to the Ms8. 0 Wenchuan EQ of 2008 are studied. The results show that in the medium-term period before the EQ, noticeable anomalies appeared synchronously at four stations around the Songpan-Ganzi active block, but only weak upward changes were observed in the short-term period preceding the EQ, which caused the prediction of the imminent EQ to fail. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.