Analog Seismogram Archives at the Earthquake Research Institute, the University of Tokyo

2020 ◽  
Vol 91 (3) ◽  
pp. 1384-1393 ◽  
Author(s):  
Kenji Satake ◽  
Hiroshi Tsuruoka ◽  
Satoko Murotani ◽  
Kenshiro Tsumura

Abstract The Earthquake Research Institute (ERI) of the University of Tokyo maintains archives of analog seismograms and mareograms. The main collection is ∼236,000 Japanese historical seismograms recorded at the University of Tokyo (at various buildings and using various instruments around Hongo [Tokyo] with a total of 189,000 records from 1881 to 1993), at the Tsukuba observatory (∼11,000 records from 1921 to 1986), and at the Wakayama seismological network (∼12,650 records from 1928 to 1968). Seismograms recorded by temporal stations at various locations in Japan for several years, typically following large earthquakes, are also included. Different types of instruments were used to record the data. The oldest record from a large earthquake is from the 1891 Nobi earthquake recorded at Hongo on a circular seismogram using an Ewing-type seismograph. Teleseismic seismograms include those from the 1899 Alaska earthquake at Hongo on an Omori-type seismograph. Imamura-type and Omori-type tremometers and strong-motion seismographs had also been used for a long time. While these seismograms were microfilmed by the 1990s, the original smoked paper records have also been archived. Foreign seismogram collections include those from earthquakes in Taiwan between 1904 and 1917 recorded in both Japan and Taiwan and those from the Canadian Seismograph Network between 1981 and 1989. For the Worldwide Standardized Seismograph Network stations, almost all (∼5,000,000) microfilm records at 167 stations from 1963 to 1988 are archived. High-resolution image scanning of analog daily seismograms at the Wakayama microearthquake network is currently being performed, and the scans are provided using Leaflet software so that the users can easily access and enlarge parts of seismograms. The tsunami waveform archive contains ∼3100 records on Japanese tide gauges from large earthquakes between 1911 and 1996. The available data, with dates and types of instruments, can be searched from the database through the website of the ERI.

Author(s):  
Musavver Didem Cambaz ◽  
Mehmet Özer ◽  
Yavuz Güneş ◽  
Tuğçe Ergün ◽  
Zafer Öğütcü ◽  
...  

Abstract As the earliest institute in Turkey dedicated to locating, recording, and archiving earthquakes in the region, the Kandilli Observatory and Earthquake Research Institute (KOERI) has a long history in seismic observation, which dates back to the installation of its first seismometers soon after the devastating Istanbul earthquake of 10 July 1894. For over a century, since the deployment of its first seismometer, the KOERI seismic network has grown steadily in time. In this article, we present the KOERI seismic network facilities as a data center for the seismological community, providing data and services through the European Integrated Data Archive (EIDA) and the Rapid Raw Strong-Motion (RRSM) database, both integrated in the Observatories and Research Facilities for European Seismology (ORFEUS). The objective of this article is to provide an overview of the KOERI seismic services within ORFEUS and to introduce some of the procedures that allow to check the health of the seismic network and the quality of the data recorded at KOERI seismic stations, which are shared through EIDA and RRSM.


2020 ◽  
Author(s):  
Seyhan Okuyan Akcan ◽  
Can Zulfikar

<p>Marmara region located on the western end of the North Anatolian Fault Zone is a tectonically active region in Turkey. There have been frequent severe earthquakes in the region and will continue to occur. There was no serious earthquake in the region after the 1999 Mw7.4 Kocaeli and Mw7.2 Düzce earthquakes. A Marmara Sea offshore earthquake Mw5.8 close to Silivri Town of Istanbul Metropolitan City has occurred on September 26, 2019 daytime at 13:59. The earthquake happened at the coordinate of 40.87N – 28.19E with a depth of 7.0km on the Kumburgaz segment of the North Anatolian Fault line. It was felt in almost all Marmara region. In some settlements in Istanbul City, slight to moderate damages were observed. A foreshock earthquake of Mw4.8 occurred on the same segment on 24 September, 2019. 150 aftershock events ranging from M1.0 to M4.1 have been recorded within the 24 hours after the mainshock. The ground motions have been recorded in the region by the several institutions including AFAD (Disaster and Emergency Management Presidency), KOERI (Kandilli Observatory and Earthquake Research Institute) and IGDAS (Istanbul Gas Distribution Industry and Trade Inc.). The ground motion records and selected parameters have been examined in this study. The ground motion parameters (MMI, PGA, PGV, Sa, Sv, Sd) distribution have been achieved and checked by the recent NGA-West2 ground motion prediction equations (GMPEs); ASK2014, CY2014 and BSSA2014. The compatibility of the GMPEs for a moderate size Marmara Sea earthquake has been examined.</p>


2017 ◽  
Vol 12 (1) ◽  
pp. 5-5
Author(s):  
Haruo Hayashi ◽  
◽  
Kimiro Meguro ◽  
Keiko Tamura

Based on the lessons from the 2011 Great East Japan Earthquake Disaster, the Ministry of Education, Culture, Sports, Science and Technology has launched “Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters (2012–2016)” with the aim of reducing the damages caused by the urban earthquake disasters such as the projected earthquake that directly hits Tokyo area and the Tokai, Tonankai and Nankai Earthquakes as much as possible. This project is divided into the following three subprojects: namely, 1) “Research and Study on Evaluation of Risk and Hazard of Earthquake that Directly Hits Tokyo Area” represented by Professor Naoshi Hirata, Earthquake Research Institute, the University of Tokyo; 2) “Research and Study on Maintenance and Recovery of Functionality in Urban Infrastructures” represented by Professor Masayoshi Nakashima, Disaster Prevention Research Institute, Kyoto University; and 3) “Research and Study on Measures to Improve Urban Resilience to Earthquake Disaster” represented by Dr. Haruo Hayashi, President of the National Research Institute for Earth Science and Disaster Resilience. This special issue focuses on the findings of the subproject 3). The subproject 3) aims to develop the information communication system for supporting efficient management of emergency responses and restoration efforts and promotion of the capabilities for solution of the problems in terms of disaster, i.e. disaster management literacy, to contribute to high resilience to disaster in our society.


Nature ◽  
1937 ◽  
Vol 139 (3519) ◽  
pp. 615-616
Author(s):  
Charles Davison

1996 ◽  
pp. 17
Author(s):  
John Anderson ◽  
Roberto Quaas ◽  
Quigbin Chen ◽  
David Almora ◽  
Ricardo Vázquez ◽  
...  

Aceelerograms recorded on the Guerrero, Mexico, strong motion accelerograph network illustrate the dependence of strong ground motion on the magnitude and the hypocenter distance. These data suppport the hipothesis that complexity in accelerograms at short distances arises from complexity at the source. The duration of strong shaking is controlled by the source dimension at short distances, and  extended by wave porpagation effects as distance increases. Peak amplitudes (peak acceleration, velocity)  saturate at different magnitudes at different distances. This change in shape of attenuation curves as magnitude increases can be explained by the trnasition of Green's functions from simple, short pulses at short distances to longer duration wave trains at large distances. Spectral amplitudes demonstrate scalin relations in which loe frequency amplitudes are proportional to seismic moment but high frecuencies increase much less rapidly. The beginnings of large earthquakes look like small earthquakes, consistent with a cascade model for the growth of large events. The mostrecent large earthquake, on sept. 14,995 (Mw=7.4) shows surprisingly weak peak accelerations.


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