Geophysical Institute of Peru

Lima, Peru

Geophysical Institute of Peru

Lima, Peru
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Cabezas D.P.,Geophysical Institute of Peru | Cabezas D.P.,San Luis Gonzaga National University | Cabezas D.P.,Kyoto University | Martinez L.M.,San Luis Gonzaga National University | And 14 more authors.
Astrophysical Journal | Year: 2017

Coronal disturbances associated with solar flares, such as Hα Moreton waves, X-ray waves, and extreme ultraviolet (EUV) coronal waves, are discussed herein in relation to magnetohydrodynamic fast-mode waves or shocks in the corona. To understand the mechanism of coronal disturbances, full-disk solar observations with high spatial and temporal resolution over multiple wavelengths are of crucial importance. We observed a filament eruption, whose shape is like a "dandelion," associated with the M1.6 flare that occurred on 2011 February 16 in Hα images taken by the Flare Monitoring Telescope at Ica University, Peru. We derive the three-dimensional velocity field of the erupting filament. We also identify winking filaments that are located far from the flare site in the Hα images, whereas no Moreton wave is observed. By comparing the temporal evolution of the winking filaments with those of the coronal wave seen in the EUV images data taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and by the Extreme Ultraviolet Imager on board the Solar Terrestrial Relations Observatory-Ahead, we confirm that the winking filaments were activated by the EUV coronal wave. © 2017. The American Astronomical Society. All rights reserved..

Huggel C.,University of Zürich | Scheel M.,University of Zürich | Albrecht F.,International Institute For Applied Systems Analysis | Albrecht F.,University of Vienna | And 13 more authors.
Environmental Science and Policy | Year: 2015

As significant impacts of climate change are increasingly considered unavoidable, adaptation has become a policy priority. It is generally agreed that science is important for the adaptation process but specific guidance on how and to what degree science should contribute and be embedded in this process is still limited which is at odds with the high demand for science contributions to climate adaptation by international organizations, national governments and others. Here we present and analyze experiences from the tropical Andes based on a recent science-policy process on the national and supra-national government level. During this process a framework for the science contribution in climate adaptation has been developed; it consists of three stages, including (1) the framing and problem definition, (2) the scientific assessment of climate, impacts, vulnerabilities and risks, and (3) the evaluation of adaptation options and their implementation. A large amount of methods has been analyzed for stage (2), and a number of major climate adaptation projects in the region assessed for (3). Our study underlines the importance of joint problem framing among various scientific and non-scientific actors, definition of socio-environmental systems, time frames, and a more intense interaction of social and physical climate and impact sciences. Scientifically, the scarcity of environmental, social and economic data in regions like the Andes continue to represent a limitation to adaptation, and further investments into coordinated socio-environmental monitoring, data availability and sharing are essential. © 2014.

Kelley M.C.,Cornell University | Ilma R.R.,Cornell University | Nicolls M.,SRI International | Erickson P.,Massachusetts Institute of Technology | And 4 more authors.
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2010

In November 2004, a major magnetic storm occurred, a lengthy portion of which was recorded by the Upper Atmospheric Radar Chain. On the 9th and 10th, the Jicamarca Radar detected the highest magnitude penetrating electric fields (±3 mV/m) and vertical drifts (±120 m/s) ever seen at this premiere facility. These large and variable drifts were highly correlated with the interplanetary magnetic and electric fields and created a double F layer on the dayside and unusual TEC behavior throughout the low-latitude zone. These solar wind-induced drifts both suppressed and generated irregularities at the magnetic equator at different times. Large-scale thermospheric disturbances were generated by high-latitude heating and tracked through the middle- to low-latitude zones where both parallel and perpendicular plasma drifts created major ionospheric changes. The auroral oval was located at a magnetic L shell of about three for many hours. © 2009 Elsevier Ltd. All rights reserved.

Arango M.C.,Imperial College London | Strasser F.O.,Seismology Unit | Bommer J.J.,Imperial College London | Boroschek R.,University of Chile | And 2 more authors.
Journal of Seismology | Year: 2010

Earthquake hazard along the Peru-Chile subduction zone is amongst the highest in the world. The development of a database of subduction-zone strong-motion recordings is, therefore, of great importance for ground-motion prediction in this region. Accelerograms recorded by the different networks operators in Peru and Chile have been compiled and processed in a uniform manner, and information on the source parameters of the causative earthquakes, fault-plane geometries and local site conditions at the recording stations has been collected and reviewed to obtain high-quality metadata. The compiled database consists of 98 triaxial ground-motion recordings from 15 subduction-type events with moment magnitudes ranging from 6.3 to 8.4, recorded at 59 different sites in Peru and Chile, between 1966 and 2007. While the database presented in this study is not sufficient for the derivation of a new predictive equation for ground motions from subduction events in the Peru-Chile region, it significantly expands the global database of strong-motion data and associated metadata that can be used in the derivation of predictive equations for subduction environments. Additionally, the compiled database will allow the assessment of existing predictive models for subduction-type events in terms of their suitability for the Peru-Chile region, which directly influences seismic hazard assessment in this region. © 2010 Springer Science+Business Media B.V.

Miyoshi M.,Japan National Astronomical Observatory | Kasuga T.,Hosei University | Iba J.K.I.,Geophysical Institute of Peru | Oka T.,Keio University | And 5 more authors.
Advances in Astronomy | Year: 2016

Imaging a black hole horizon as a shadow at the center of black hole accretion disk is another method to prove/check Einstein's general relativity at strong gravitational fields. Such black hole imaging is expected to be achievable using a submillimeter wavelength VLBI (very long baseline interferometer) technique. Here, we introduce a Japanese black hole imaging project, Caravan-submm undertaken in the Andes. © 2016 Makoto Miyoshi et al.

Arango M.C.,Imperial College London | Strasser F.O.,Seismology Unit | Strasser F.O.,Arup | Bommer J.J.,Imperial College London | And 4 more authors.
Bulletin of the Seismological Society of America | Year: 2012

The applicability of existing ground-motion prediction equations (GMPEs) for subduction-zone earthquakes is an important issue to address in the assessment of the seismic hazard affecting the Peru-Chile and Central American regions. Few predictive equations exist that are derived from local data, and these do not generally meet the quality criteria required for use in modern seismic hazard analyses. This paper investigates the applicability of a set of global and regional subduction ground-motion models to the Peru-Chile and Central American subduction zones, distinguishing between interface and intraslab events, in light of recently compiled ground-motion data from these regions. Strong-motion recordings and associated metadata compiled by Arango, Strasser, Bommer, Boroschek, et al. (2011) and Arango, Strasser, Bommer, Hernandez, et al. (2011) have been used to assess the performance of the candidate equations following the maximum-likelihood approach of Scherbaum et al. (2004) and its extension to normalized intraevent and interevent residual distributions developed by Stafford et al. (2008). The results of this study are discussed in terms of the transportability of GMPEs for subduction-zone environments from one region to another, with a view to providing guidance for developing groundmotion logic trees for seismic hazard analysis in these regions.

Yauri S.,Geophysical Institute of Peru | Fujii Y.,Japan Building Research Institute | Shibazaki B.,Japan Building Research Institute
Bulletin of the International Institute of Seismology and Earthquake Engineering | Year: 2012

A comprehensive study of tsunami simulation for the two recent events in 1974 (Mw8.0), 1966 (Mw8.1) and one historical event in 1746 (Mw8.5-9.2) was carried out in order to constrain the tsunami source and evaluate the tsunami hazard in the central coast of Peru. We propose a seismic source for each event in 1974 and 1966 and evaluate the tsunami heights and arrival time by performing a tsunami simulation using a TUNAMI-N2 code that solves non-linear long wave equation. Also, in order to reproduce the historical tsunami in 1746, we carried out a simulation for scenarios with Mw of 8.5, 8.8, 9.0 and 9.2. Through a comparison among the historical tsunami descriptions, the scenarios with Mw 8.8-9.0 were found to be more representatives, which is consistent with the maximum tsunami heights observed from Huarmey to Barranco stations. Moreover, we adopt a more realistic future tsunami scenario using a predicted slip model from an interseismic coupling using GPS data provided by Pulido et al. (2011). This scenario shows an important coupling area facing Huacho Lima and Pisco cities and according to the moment deficit a repetitive event of the 1746 earthquake could occur. Also this model shows that the events in 1940, 1966, 1974 and 2007 have not released the total energy accumulated since 1746. From this scenario, the maximum tsunami height could be 7.8 m in Huacho station with a minimum arrival time of 25 min after the earthquake. In all the cases, we found that the tsunami travels faster to the south and slower to the north of Peru. The tsunami simulation using the bathymetry data of 30 arc-second resolution showed longer travel time and higher amplitude compared with the 1 arc-minute resolution, giving the former better results in the comparison between the synthetic and observed tide gauge records for the 1974 and 1966 events.

Takla E.M.,Kyushu University | Takla E.M.,National Research Institute of Astronomy and Geophysics | Yumoto K.,Kyushu University | Ishitsuka J.,Geophysical Institute of Peru | And 4 more authors.
Tectonophysics | Year: 2012

On 15 August 2007, Pisco earthquake (magnitude 8.0) hit the central coast of Peru near the MAGDAS Ancon (ANC) station. Geomagnetic data from ANC and other reference stations have been analyzed to detect any signature related to this great earthquake. Results indicate the presence of annual geomagnetic variations in the vertical component at ANC and Huancayo (HUA) stations (in the vicinity of the epicenter of Pisco earthquake). These variations have a quasi-sinusoidal waveform with amplitudes of about 10 and 5. nT for ANC and HUA stations respectively. They appeared clearly during the period preceding the onset of the Pisco earthquake especially at ANC station. By using HUA, Eusebio (EUS) and Kourou (KOU) as reference stations in the vicinity and away from the epicenter of Pisco earthquake, a clear disappearance of the diurnal variation of the vertical component was observed at ANC station during the day of earthquake. Moreover, the Pisco earthquake and another earthquake (on 29 March 2008) near ANC station were found to occur concurrently with the depressions in the polarization ratio (Z/H) of Pc 3 (10-45. s) amplitude. Such anomalous variations appear to be a result of changes in the crustal stress field and the lithospheric conductivity in the studied region. © 2011 Elsevier B.V.

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