A Database of Digitized and Analog Seismograms of Historical Earthquakes in Japan

2020 ◽  
Vol 91 (3) ◽  
pp. 1459-1468
Author(s):  
Satoko Murotani ◽  
Kenji Satake ◽  
Hiroshi Tsuruoka ◽  
Hiroe Miyake ◽  
Toshiaki Sato ◽  
...  
Keyword(s):  
Earthquake Engineering ◽  
High Performance ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
Current Knowledge ◽  
Historical Earthquakes ◽  
Disaster Mitigation ◽  
Waveform Analysis ◽  
Historical Records ◽  
Earthquake Research

Abstract Seismic and tsunami instrumental observations by seismographs and tide gauges began in Japan in 1875; hence, many analog records of earthquakes and tsunamis are stored at various universities and institutions throughout the country. Re-examination of historical records using modern waveform analysis methods, high-performance computing, and current knowledge on seismic velocity structure is expected to produce new results and interpretations of the mechanism of large earthquakes and tsunamis, leading to improved seismic disaster mitigation practices. However, such work requires extensive effort and skills for the digitization of the analog waveforms recorded on papers. To conveniently use the analog seismograms, we currently construct a database of digitized historical records and seismogram image copies of major earthquakes that occurred in Japan (e.g., the 1923 Kanto, 1944 Tonankai, and 1946 Nankai earthquakes). The data can be searched in this database by event, station, and seismograph names. Users can obtain the instrumental response and station information, if available, in addition to the digitized data. We plan to open this database to the public in a few years via the National Museum of Nature and Science and the Earthquake Research Institute of the University of Tokyo. The database on the museum website will be fundamental for outreach activity of seismology for the general public, and the information contained in the database will be useful in various fields such as seismology or earthquake engineering.

The NSF Earthquake Disaster Mitigation Research Program

1998 ◽  
Vol 14 (3) ◽  
pp. 433-440 ◽  
Author(s):  
S. C. Liu ◽  
W. Anderson ◽  
C. Astill ◽  
L. Weber
Keyword(s):  
Earthquake Engineering ◽  
Research Program ◽  
High Performance ◽  
Earthquake Hazard ◽  
Disaster Mitigation ◽  
Earthquake Simulation ◽  
Cooperative Research ◽  
Earthquake Disaster ◽  
Engineering Research ◽  
The U.S

This paper presents several major developments and research initiatives of NSF's program in earthquake hazard mitigation. These activities include (1) establishment of three new earthquake engineering research centers in the U.S., (2) initiation of a major five-year cooperative research program on urban earthquake disaster mitigation between the U.S. and Japan, (3) initiation of two joint center-to-center projects between the U.S. and Japan, and (4) planning for a high-performance earthquake simulation facility network in the U.S. These activities highlight the ever-increasing importance of research innovations for earthquake disaster mitigation and the continuing challenges for cooperation between the U.S. and Japan.

scholarly journals NHERI@UC San Diego 6-DOF Large High-Performance Outdoor Shake Table Facility

2021 ◽  
Vol 6 ◽  
Author(s):  
Lelli Van Den Einde ◽  
Joel P. Conte ◽  
José I. Restrepo ◽  
Ricardo Bustamante ◽  
Marty Halvorson ◽  
...  
Keyword(s):  
Seismic Response ◽  
Earthquake Engineering ◽  
San Diego ◽  
High Performance ◽  
Large Scale ◽  
Computational Models ◽  
Disaster Mitigation ◽  
Structural Systems ◽  
Shake Table ◽  
The Impact

Since its commissioning in 2004, the UC San Diego Large High-Performance Outdoor Shake Table (LHPOST) has enabled the seismic testing of large structural, geostructural and soil-foundation-structural systems, with its ability to accurately reproduce far- and near-field ground motions. Thirty-four (34) landmark projects were conducted on the LHPOST as a national shared-use equipment facility part of the National Science Foundation (NSF) Network for Earthquake Engineering Simulation (NEES) and currently Natural Hazards Engineering Research Infrastructure (NHERI) programs, and an ISO/IEC Standard 17025:2005 accredited facility. The tallest structures ever tested on a shake table were conducted on the LHPOST, free from height restrictions. Experiments using the LHPOST generate essential knowledge that has greatly advanced seismic design practice and response predictive capabilities for structural, geostructural, and non-structural systems, leading to improved earthquake safety in the community overall. Indeed, the ability to test full-size structures has made it possible to physically validate the seismic performance of various systems that previously could only be studied at reduced scale or with computer models. However, the LHPOST's limitation of 1-DOF (uni-directional) input motion prevented the investigation of important aspects of the seismic response of 3-D structural systems. The LHPOST was originally conceived as a six degrees-of-freedom (6-DOF) shake table but built as a single degree-of-freedom (1-DOF) system due to budget limitations. The LHPOST is currently being upgraded to 6-DOF capabilities. The 6-DOF upgraded LHPOST (LHPOST6) will create a unique, large-scale, high-performance, experimental research facility that will enable research for the advancement of the science, technology, and practice in earthquake engineering. Testing of infrastructure at large scale under realistic multi-DOF seismic excitation is essential to fully understand the seismic response behavior of civil infrastructure systems. The upgraded 6-DOF capabilities will enable the development, calibration, and validation of predictive high-fidelity mathematical/computational models, and verifying effective methods for earthquake disaster mitigation and prevention. Research conducted using the LHPOST6 will improve design codes and construction standards and develop accurate decision-making tools necessary to build and maintain sustainable and disaster-resilient communities. Moreover, it will support the advancement of new and innovative materials, manufacturing methods, detailing, earthquake protective systems, seismic retrofit methods, and construction methods. This paper will provide a brief overview of the 1-DOF LHPOST and the impact of some past landmark projects. It will also describe the upgrade to 6-DOF and the new seismic research and testing that the LHPOST6 facility will enable.

scholarly journals Seismic velocity structure at the southern termination of the 2016 Kumamoto Earthquake rupture, Japan

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Yasuhira Aoyagi ◽  
Haruo Kimura ◽  
Kazuo Mizoguchi
Keyword(s):  
Fault Zone ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
Earthquake Rupture ◽  
2016 Kumamoto Earthquake ◽  
Seismic Velocity Structure ◽  
Kumamoto Earthquake ◽  
Seismogenic Layer ◽  
The 2016 Kumamoto Earthquake ◽  
Tectonic Line

Abstract The earthquake rupture termination mechanism and size of the ruptured area are crucial parameters for earthquake magnitude estimations and seismic hazard assessments. The 2016 Mw 7.0 Kumamoto Earthquake, central Kyushu, Japan, ruptured a 34-km-long area along previously recognized active faults, eastern part of the Futagawa fault zone and northernmost part of the Hinagu fault zone. Many researchers have suggested that a magma chamber under Aso Volcano terminated the eastward rupture. However, the termination mechanism of the southward rupture has remained unclear. Here, we conduct a local seismic tomographic inversion using a dense temporary seismic network to detail the seismic velocity structure around the southern termination of the rupture. The compressional-wave velocity (Vp) results and compressional- to shear-wave velocity (Vp/Vs) structure indicate several E–W- and ENE–WSW-trending zonal anomalies in the upper to middle crust. These zonal anomalies may reflect regional geological structures that follow the same trends as the Oita–Kumamoto Tectonic Line and Usuki–Yatsushiro Tectonic Line. While the 2016 Kumamoto Earthquake rupture mainly propagated through a low-Vp/Vs area (1.62–1.74) along the Hinagu fault zone, the southern termination of the earthquake at the focal depth of the mainshock is adjacent to a 3-km-diameter high-Vp/Vs body. There is a rapid 5-km step in the depth of the seismogenic layer across the E–W-trending velocity boundary between the low- and high-Vp/Vs areas that corresponds well with the Rokkoku Tectonic Line; this geological boundary is the likely cause of the dislocation of the seismogenic layer because it is intruded by serpentinite veins. A possible factor in the southern rupture termination of the 2016 Kumamoto Earthquake is the existence of a high-Vp/Vs body in the direction of southern rupture propagation. The provided details of this inhomogeneous barrier, which are inferred from the seismic velocity structures, may improve future seismic hazard assessments for a complex fault system composed of multiple segments.

Crustal Structure across Central Scandinavian Peninsula along Silver Road refraction profile

2021 ◽  
Author(s):  
Metin Kahraman ◽  
Hans Thybo ◽  
Irina Artemieva ◽  
Alexey Shulgin ◽  
Alireza Malehmir ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Baltic Shield ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
Seismic Profile ◽  
High Mountain ◽  
Mountain Range ◽  
Air Gun ◽  
The Baltic

<p>The Baltic Shield is located in the northern part of Europe, which formed by amalgamation of a series of terranes and microcontinents during the Archean to the Paleoproterozoic, followed by significant modification in Neoproterozoic to Paleozoic time. The Baltic Shield includes an up-to 2500 m high mountain range, the Scandes , along the western North Atlantic coast, despite being a stable craton located far from any active plate boundary.</p><p>We study a crustal scale seismic profile experiment in northern Scandinavia between 63<sup>o</sup>N and 71<sup>o</sup>N. Our Silverroad seismic profile extends perpendicular to the coastline around Lofoten and extends ~300km in a northwest direction across the shelf into the Atlantic Ocean and ~300km in a southeastern direction across the Baltic Shield. The seismic data were acquired with 5 explosive sources and 270 receivers onshore; 16 ocean bottom seismometers and air gun shooting from the vessel Hakon Mosby were used to collect both offshore and onshore.</p><p>We present the results from raytracing modelling of the seismic velocity structure along the profile. The outputs of this experiment will help to solve high onshore topography and anomalous and heterogeneous bathymetry of the continental lithosphere around the North Atlantic Ocean. The results show crustal thinning from the shield onto the continental shelf and further into the oceanic part. Of particular interest is the velocity below the high topography of the Scandes, which will be discussed in relation to isostatic equilibrium along the profile.</p>

Seismic tomographic interpretation of Paleozoic sedimentary sequences in the southeastern North Sea

Geophysics ◽  
2005 ◽  
Vol 70 (4) ◽  
pp. R45-R56 ◽  
Author(s):  
Lars Nielsen ◽  
Hans Thybo ◽  
Martin Glendrup
Keyword(s):  
North Sea ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
P Wave ◽  
Wide Angle ◽  
North German Basin ◽  
Sedimentary Sequences ◽  
The North ◽  
Crystalline Crust ◽  
German Basin

Seismic wide-angle data were recorded to more than 300-km offset from powerful airgun sources during the MONA LISA experiments in 1993 and 1995 to determine the seismic-velocity structure of the crust and uppermost mantle along three lines in the southeastern North Sea with a total length of 850 km. We use the first arrivals observed out to an offset of 90 km to obtain high-resolution models of the velocity structure of the sedimentary layers and the upper part of the crystalline crust. Seismic tomographic traveltime inversion reveals 2–8-km-thick Paleozoic sedimentary sequences with P-wave velocities of 4.5–5.2 km/s. These sedimentary rocks are situated below a Mesozoic-Cenozoic sequence with variable thickness: ∼2–3 km on the basement highs, ∼2–4 km in the Horn Graben and the North German Basin, and ∼6–7 km in the Central Graben. The thicknesses of the Paleozoic sedimentary sequences are ∼3–5 km in the Central Graben, more than 4 km in the Horn Graben, up to ∼4 km on the basement highs, and up to 8 km in the North German Basin. The Paleozoic strata are clearly separated from the shallower and younger sequences with velocities of ∼1.8–3.8 km/s and the deeper crystalline crust with velocities of more than 5.8–6.0 km/s in the tomographic P-wave velocity model. Resolution tests show that the existence of the Paleozoic sediments is well constrained by the data. Hence, our wide-angle seismic models document the presence of Paleozoic sediments throughout the southeastern North Sea, both in the graben structures and in deep basins on the basement highs.

scholarly journals High-Performance Computing of BEAST/BEAGLE in Bayesian Phylogenetics using SDumont Hybrid Resources

2020 ◽  
Author(s):  
Kary Ocaña ◽  
Micaella Coelho ◽  
Guilherme Freire ◽  
Carla Osthoff
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
Current Knowledge ◽  
Data Sets ◽  
Length Estimation ◽  
Computationally Intensive ◽  
Mcmc Chain ◽  
Performance Computing ◽  
Insight Into

Bayesian phylogenetic algorithms are computationally intensive. BEAST 1.10 inferences made use of the BEAGLE 3 high-performance library for efficient likelihood computations. The strategy allows phylogenetic inference and dating in current knowledge for SARS-CoV-2 transmission. Follow-up simulations on hybrid resources of Santos Dumont supercomputer using four phylogenomic data sets, we characterize the scaling performance behavior of BEAST 1.10. Our results provide insight into the species tree and MCMC chain length estimation, identifying preferable requirements to improve the use of high-performance computing resources. Ongoing steps involve analyzes of SARS-CoV-2 using BEAST 1.8 in multi-GPUs.

scholarly journals Travel Time Tomography to Delineate 3-D Regional Seismic Velocity Structure in the Banyumas Basin, Central Java, Indonesia, Using Dense Borehole Seismographic Stations

2021 ◽  
Vol 9 ◽  
Author(s):  
Hidayat Hidayat ◽  
Andri Dian Nugraha ◽  
Awali Priyono ◽  
Marjiyono Marjiyono ◽  
Januar H. Setiawan ◽  
...  
Keyword(s):  
Velocity Structure ◽  
Seismic Velocity ◽  
Velocity Model ◽  
Crustal Layer ◽  
Central Java ◽  
Resolution Element ◽  
Passive Seismic ◽  
Dextral Strike Slip Fault ◽  
Southern Central ◽  
Well Data

The Banyumas Basin is a tertiary sedimentary basin located in southern Central Java, Indonesia. Due to the presence of volcanic deposits, 2-D seismic reflection methods cannot provide a good estimation of the sediment thickness and the subsurface geology structure in this area. In this study, the passive seismic tomography (PST) method was applied to image the 3-D subsurface Vp, Vs, and Vp/Vs ratio. We used 70 seismograph borehole stations with a recording duration of 177 days. A total of 354 events with 9, 370 P and 9, 368 S phases were used as input for tomographic inversion. The checkshot data of a 4, 400-meter deep exploration well (Jati-1) located within the seismic network were used to constrain the shallow crustal layer of the initial 1-D velocity model. The model resolution of the tomographic inversions was assessed using the checkerboard resolution test (CRT), the diagonal resolution element (DRE), and the derivative weight sum (DWS). Using the obtained Vp, Vs, and Vp/Vs ratio, we were able to sharpen details of the geological structures within the basin from previous geological studies, and a fault could be well-imaged at a depth of 4 km. We interpreted this as the main dextral strike-slip fault that controls the pull apart process of the Banyumas Basin. The thickness of the sediment layers, as well as its layering, were also could be well determined. We found prominent features of the velocity contrast that aligned very well with the boundary between the Halang and Rambatan formations as observed in the Jati-1 well data. Furthermore, an anticline structure, which is a potential structural trap for the petroleum system in the Banyumas Basin, was also well imaged. This was made possible due to the dense borehole seismographic stations which were deployed in the study area.

scholarly journals Severe and regionally-widespread increases in tissue urea in the human brain represent a novel finding of pathogenic potential in Parkinson’s disease dementia

2021 ◽  
Author(s):  
Melissa Scholefield ◽  
Stephanie J. Church ◽  
Jingshu Xu ◽  
Stefano Patassini ◽  
Federico Roncaroli ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
High Performance ◽  
Current Knowledge ◽  
Neuronal Loss ◽  
Middle Temporal Gyrus ◽  
Parkinson’S Disease Dementia ◽  
Pathogenic Potential ◽  
Age Related ◽  
Liquid Chromatography Tandem Mass

Abstract Background: Widespread elevations in brain urea have, in recent years, been reported in certain types of age-related dementia, notably Alzheimer’s disease (AD) and Huntington’s disease (HD). Urea increases in these diseases are substantive, and approximate in magnitude to levels present in uraemic encephalopathy. In AD and HD, elevated urea levels occur across the entire brain, and not only in regions heavily affected by neurodegeneration. However, measurements of brain urea have not hitherto been reported in Parkinson’s disease dementia (PDD), a condition defined by changes in thinking and behaviour in someone with a diagnosis of Parkinson's disease, which shares neuropathological and symptomatic overlap with both AD and HD. This study aims to address this gap in the current knowledge of PDD.Methods: Here we report measurements of tissue urea from nine neuropathologically-confirmed regions of the brain in PDD and post-mortem-delay-matched controls, in regions that included the cerebellum, motor cortex, sensory cortex, hippocampus, substantia nigra, middle temporal gyrus, medulla oblongata, cingulate gyrus, and pons, by applying ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Case-control differences were determined using multiple t-tests followed by correction with 10% false discovery rate.Results: We found urea concentrations to be substantively elevated in all nine regions, the average increase being 3-4-fold. Urea concentrations were remarkably consistent across regions in both cases and controls, with no clear distinction between regions heavily affected by neuronal loss in PDD compared to less severely affected areas. These urea elevations mirror those found in uraemic encephalopathy, where equivalent levels are generally considered to be pathogenic. These urea elevations also reflect those previously reported in AD and HD. Conclusions: Increased urea is a widespread metabolic perturbation in brain metabolism common to PDD, AD, and HD, at levels equal to those seen in uremic encephalopathy. This presents a novel pathogenic mechanism in PDD, which is shared with two other neurodegenerative diseases.

scholarly journals Current knowledge in hypertension genetics: mosaic theory, candidate genes and genome-wide association studies

2020 ◽  
Vol 26 (5) ◽  
pp. 490-500
Author(s):  
A. O. Konradi
Keyword(s):  
Candidate Genes ◽  
High Performance ◽  
New Technologies ◽  
Current Knowledge ◽  
Association Studies ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Modern Approach ◽  
Genome Wide

The article reviews monogenic forms of hypertension, data on the role of heredity of essential hypertension and candidate genes, as well as genome-wide association studies. Modern approach for the role of genetics is driven by implementation of new technologies and their productivity. High performance speed of new technologies like genome-wide association studies provide data for better knowledge of genetic markers of hypertension. The major goal nowadays for research is to reveal molecular pathways of blood pressure regulation, which can help to move from populational to individual level of understanding of pathogenesis and treatment targets.

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