A novel strong-motion seismic network for community participation in earthquake monitoring

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.

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Real-time seismology at UC Berkeley: The Rapid Earthquake Data Integration project

Bulletin of the Seismological Society of America ◽

10.1785/bssa0860040936 ◽

1996 ◽

Vol 86 (4) ◽

pp. 936-945 ◽

Cited By ~ 2

Author(s):

Lind S. Gee ◽

Douglas S. Neuhauser ◽

Douglas S. Dreger ◽

Michael E. Pasyanos ◽

Robert A. Uhrhammer ◽

...

Keyword(s):

Data Integration ◽

Strong Motion ◽

Seismic Network ◽

Prototype System ◽

Earthquake Parameters ◽

Moment Tensors ◽

Automatic Information ◽

Integration Project ◽

Earthquake Data

Abstract The Rapid Earthquake Data Integration project is a system for the fast determination of earthquake parameters in northern and central California based on data from the Berkeley Digital Seismic Network and the USGS Northern California Seismic Network. Program development started in 1993, and a prototype system began providing automatic information on earthquake location and magnitude in November of 1993 via commercial pagers and the Internet. Recent enhancements include the exchange of phase data with neighboring networks and the inauguration of processing for the determination of strong-motion parameters and seismic moment tensors.

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2019 Ridgecrest Earthquake Reveals Areas of Los Angeles That Amplify Shaking of High-Rises

Seismological Research Letters ◽

10.1785/0220200170 ◽

2020 ◽

Vol 91 (6) ◽

pp. 3370-3380

Author(s):

Monica D. Kohler ◽

Filippos Filippitzis ◽

Thomas Heaton ◽

Robert W. Clayton ◽

Richard Guy ◽

...

Keyword(s):

Los Angeles ◽

Strong Motion ◽

Ground Level ◽

Site Amplification ◽

Seismic Network ◽

Los Angeles Basin ◽

High Rise ◽

The North ◽

South Central ◽

San Fernando

Abstract The populace of Los Angeles, California, was startled by shaking from the M 7.1 earthquake that struck the city of Ridgecrest located 200 km to the north on 6 July 2019. Although the earthquake did not cause damage in Los Angeles, the experience in high-rise buildings was frightening in contrast to the shaking felt in short buildings. Observations from 560 ground-level accelerometers reveal large variations in shaking in the Los Angeles basin that occurred for more than 2 min. The observations come from the spatially dense Community Seismic Network (CSN), combined with the sparser Southern California Seismic Network and California Strong Motion Instrumentation Program networks. Site amplification factors for periods of 1, 3, 6, and 8 s are computed as the ratio of each station’s response spectral values combined for the two horizontal directions, relative to the average of three bedrock sites. Spatially coherent behavior in site amplification emerges for periods ≥3 s, and the maximum calculated site amplifications are the largest, by factors of 7, 10, and 8, respectively, for 3, 6, and 8 s periods. The dense CSN observations show that the long-period amplification is clearly, but only partially, correlated with the depth to basement. Sites with the largest amplifications for the long periods (≥3 s) are not close to the deepest portion of the basin. At 6 and 8 s periods, the maximum amplifications occur in the western part of the Los Angeles basin and in the south-central San Fernando Valley sedimentary basin. The observations suggest that the excitation of a hypothetical high-rise located in an area characterized by the largest site amplifications could be four times larger than in a downtown Los Angeles location.

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The study of key issues about integration of GNSS and strong-motion records for real-time earthquake monitoring

Advances in Space Research ◽

10.1016/j.asr.2016.04.033 ◽

2016 ◽

Vol 58 (3) ◽

pp. 304-309 ◽

Cited By ~ 2

Author(s):

Rui Tu ◽

Pengfei Zhang ◽

Rui Zhang ◽

Jinhai Liu

Keyword(s):

Real Time ◽

Strong Motion ◽

Strong Motion Records ◽

Earthquake Monitoring ◽

Key Issues

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The “TRUAA” Seismic Network: Upgrading the Israel Seismic Network—Toward National Earthquake Early Warning System

Seismological Research Letters ◽

10.1785/0220200169 ◽

2020 ◽

Vol 91 (6) ◽

pp. 3236-3255 ◽

Cited By ~ 1

Author(s):

Ittai Kurzon ◽

Ran N. Nof ◽

Michael Laporte ◽

Hallel Lutzky ◽

Andrey Polozov ◽

...

Keyword(s):

Early Warning ◽

High Speed ◽

High Capacity ◽

Strong Motion ◽

Virtual Private Network ◽

Seismic Network ◽

Earthquake Early Warning ◽

Fault System ◽

Earthquake Early Warning System ◽

Private Network

Abstract Following the recommendations of an international committee (Allen et al., 2012), since October 2017, the Israeli Seismic Network has been undergoing significant upgrades, with 120 stations being added or upgraded throughout the country and the addition of two new datacenters. These enhancements are the backbone of the TRUAA project, assigned to the Geological Survey of Israel (GSI) by the Israeli Government, to provide earthquake early warning (EEW) capabilities for the state of Israel. The GSI contracted Nanometrics (NMX), supported by Motorola Solutions Israel, to deliver these upgrades through a turnkey project, including detailed design, equipment supply, and deployment of the network and two datacenters. The TRUAA network was designed and tailored by the GSI, in collaboration with the NMX project team, specifically to achieve efficient and robust EEW. Several significant features comprise the pillars of this network:Coverage: Station distribution has high density (5–10 km spacing) along the two main fault systems—the Dead Sea Fault and the Carmel Fault System;Instrumentation: High-quality strong-motion accelerometers and broadband seismometers with modern three-channel and six-channel dataloggers sampling at 200 samples per second;Low latency acquisition: Data are encapsulated in small packets (<1 s), with primary routing via high-speed, high-capacity telemetry links (<1 s latency);Robustness: High level of redundancy throughout the system design:Dual active-active redundant acquisition routes from each station, each utilizing multicast streaming over an IP security Virtual Private Network tunnel, via independent high-bandwidth telemetry systemsTwo active-active independent geographically separate datacentersDual active-active redundant independent automatic seismic processing tool chains within each datacenter, implemented in a high availability protected virtual environment. At this time, both datacenters and over 100 stations are operational. The system is currently being commissioned, with initial early warning operation targeted for early 2021.

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Methods for Amplitude Calibration and Orientation Discrepancy Measurement: Comparing Co‐Located Sensors of Different Types in the Southern California Seismic Network

Bulletin of the Seismological Society of America ◽

10.1785/0120190019 ◽

2019 ◽

Vol 109 (4) ◽

pp. 1563-1570 ◽

Cited By ~ 2

Author(s):

Zefeng Li ◽

Egill Hauksson ◽

Jennifer Andrews

Keyword(s):

Southern California ◽

Dynamic Range ◽

Strong Motion ◽

Seismic Network ◽

Motion Sensors ◽

Vertical Orientation ◽

Horizontal Orientation ◽

California Institute Of Technology ◽

Short Period ◽

Institute Of Technology

Abstract Modern seismic networks commonly equip a station with multiple sensors, to extend the frequency band and the dynamic range of data recorded at the station. In addition, in our recent study we showed that comparison of data from co‐located seismometers and accelerometers is useful for detecting instrument malfunctions and monitoring data quality. In this study, we extend comparison of data from different co‐located sensors to two other applications: (1) amplitude calibration for data from vertical short‐period sensors with strong‐motion sensors as baseline and (2) measurement of orientation discrepancy between strong‐motion and broadband sensors. We perform systematic analyses of data recorded by the California Institute of Technology/U.S. Geological Survey Southern California Seismic Network. In the first application, we compare the amplitude of data from vertical short‐period sensors to that of data from co‐located strong‐motion sensors and measure the amplitude calibration factors for 93 short‐period sensors. Among them, 49 stations are measured at ∼1.0, 42 measured at ∼0.6, as well as two outlying stations: GFF at 0.3 and CHI at 1.3. These values are found to be related to the sensors’ sensitivity values. In the second application, we measure orientation discrepancy between 222 co‐located broadband and strong‐motion sensors. All the vertical orientation differences are found to be within 5°. However, the horizontal orientation differences of 22 stations are greater than 6°, among which four stations have reverse rotation or 180° from the expected orientation. These measurements have been communicated to network operators and fixes are being applied. This study, together with our previously developed data monitoring framework, demonstrates that comparison of different co‐located sensors is a simple and effective tool for a broad range of seismic data assessment and instrument calibration.

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Community Seismic Network: A Dense Array to Sense Earthquake Strong Motion

Seismological Research Letters ◽

10.1785/0220150094 ◽

2015 ◽

Vol 86 (5) ◽

pp. 1354-1363 ◽

Cited By ~ 30

Author(s):

Robert W. Clayton ◽

Thomas Heaton ◽

Monica Kohler ◽

Mani Chandy ◽

Richard Guy ◽

...

Keyword(s):

Strong Motion ◽

Seismic Network ◽

Dense Array

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Real-time earthquake monitoring for tsunami warning in the Indian Ocean and beyond

Natural Hazards and Earth System Science ◽

10.5194/nhess-10-2611-2010 ◽

2010 ◽

Vol 10 (12) ◽

pp. 2611-2622 ◽

Cited By ~ 49

Author(s):

W. Hanka ◽

J. Saul ◽

B. Weber ◽

J. Becker ◽

P. Harjadi ◽

...

Keyword(s):

Indian Ocean ◽

Real Time ◽

Monitoring System ◽

Warning System ◽

Seismic Network ◽

Tsunami Warning ◽

Time Data ◽

Real Time Data ◽

Earthquake Monitoring ◽

The Indian Ocean

Abstract. The Mw = 9.3 Sumatra earthquake of 26 December 2004 generated a tsunami that affected the entire Indian Ocean region and caused approximately 230 000 fatalities. In the response to this tragedy the German government funded the German Indonesian Tsunami Early Warning System (GITEWS) Project. The task of the GEOFON group of GFZ Potsdam was to develop and implement the seismological component. In this paper we describe the concept of the GITEWS earthquake monitoring system and report on its present status. The major challenge for earthquake monitoring within a tsunami warning system is to deliver rapid information about location, depth, size and possibly other source parameters. This is particularly true for coast lines adjacent to the potential source areas such as the Sunda trench where these parameters are required within a few minutes after the event in order to be able to warn the population before the potential tsunami hits the neighbouring coastal areas. Therefore, the key for a seismic monitoring system with short warning times adequate for Indonesia is a dense real-time seismic network across Indonesia with densifications close to the Sunda trench. A substantial number of supplementary stations in other Indian Ocean rim countries are added to strengthen the teleseismic monitoring capabilities. The installation of the new GITEWS seismic network – consisting of 31 combined broadband and strong motion stations – out of these 21 stations in Indonesia – is almost completed. The real-time data collection is using a private VSAT communication system with hubs in Jakarta and Vienna. In addition, all available seismic real-time data from the other seismic networks in Indonesia and other Indian Ocean rim countries are acquired also directly by VSAT or by Internet at the Indonesian Tsunami Warning Centre in Jakarta and the resulting "virtual" network of more than 230 stations can jointly be used for seismic data processing. The seismological processing software as part of the GITEWS tsunami control centre is an enhanced version of the widely used SeisComP software and the well established GEOFON earthquake information system operated at GFZ in Potsdam (http://geofon.gfz-potsdam.de/db/eqinfo.php). This recently developed software package (SeisComP3) is reliable, fast and can provide fully automatic earthquake location and magnitude estimates. It uses innovative visualization tools, offers the possibility for manual correction and re-calculation, flexible configuration, support for distributed processing and data and parameter exchange with external monitoring systems. SeisComP3 is not only used for tsunami warning in Indonesia but also in most other Tsunami Warning Centres in the Indian Ocean and Euro-Med regions and in many seismic services worldwide.

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