Real-time Earthquake Research Articles

How A Smartphone Network Detects Earthquakes in Real Time

Abstract With the aid of thousands of accelerometers and some statistical know-how, Francesco Finazzi has built a crowd-sourced early warning system for major quakes

Design and realization of RS application system for earthquake emergency based on digital earth

The current RS-based earthquake emergency system is mainly based on stand-alone software which cannot meet the requirements of massive remote sensing data and parallel seismic damage information extraction after a devastating earthquake. Taking Shaanxi Province as an example, this paper explored firstly the network-based working mode of seismic damage information extraction and data management strategy for multi-user cooperative operation based on analysing work flow of the RS application to earthquake emergency. Then, using WorldWind java SDK, the RS application system for earthquake emergency based on digital earth platform was brought out in CS architecture. Finally, spatial data tables of classification and grade of seismic damage were designed and the system was developed. This system realized functions including 3D display, management of seismic RS image and GIS data obtained before and after earthquake for different user levels and cooperative extraction and publish of such seismic information as building damage, traffic damage and seismo-geological disasters caused by earthquake in real time. Some application to earthquake cases such as 2014 Ms6.5 Ludian earthquake show that this system can improve the efficiency of seismic damage information interpretation and data sharing, and provide import disaster information for decision making of earthquake emergency rescue and disaster relief.

Operational earthquake forecasting in Europe: progress, despite challenges

Is Europe-wide operational earthquake forecasting (OEF) possible? We discuss the myriad problems that prevent it today, many of which relate to heterogeneities in earthquake recording, processing, and reporting. We contemplate the difficulty of building models that cross political boundaries, and we consider the prospect of European OEF in light of recent efforts to harmonize long-term seismic hazard assessment among several nations. Emphasizing the Strategies and Tools for Real-time Earthquake Risk Reduction (REAKT) project, we report achievements related to short-term seismicity forecasting in Iceland and Italy that could apply elsewhere in Europe. In Iceland, collaboration fostered by REAKT resulted in a revised earthquake catalog and a prototype OEF system. We report results from an experiment conducted with this prototype; these results suggest ensemble models provide an information gain, updating models more frequently improves their forecast skill, and that OEF is computationally feasible. In Italy, REAKT supported the creation of an ensemble model that now issues weekly hazard forecasts. We present examples of these forecasts, highlighting the problem that OEF often yields low probabilities, which are difficult to interpret and convert into actionable decisions. Motivated by such low hazard probabilities, we highlight Europe’s pioneering efforts in operational earthquake loss forecasting and mention solutions to problems that currently prevent OEF at the European scale.

Real-time earthquake monitoring at the Indian Tsunami Early Warning System for tsunami advisories in the Indian Ocean

The Indian Tsunami Early Warning System situated at Indian National Center for Ocean Information Services, Hyderabad, India, monitors real-time earthquake activity throughout the Indian Ocean to evaluate potential tsunamigenic earthquakes. The functions of the Indian Tsunami Early Warning System earthquake monitoring system include detection, location and determination of the magnitude of potentially tsunamigenic earthquakes occurring in the Indian Ocean. The real-time seismic monitoring network comprises 17 broadband Indian seismic stations transmitting real-time earthquake data through VSAT communication to the central receiving stations located at the Indian Meteorological Department, New Delhi, and the Indian National Center for Ocean Information Services, Hyderabad, simultaneously for processing and interpretation. In addition to this, earthquake data from around 300 global seismic stations are also received at the Indian National Center for Ocean Information Services in near-real-time. Most of these data are provided by IRIS Global Seismographic Network and GEOFON Extended Virtual Network through Internet. The Indian National Center for Ocean Information Services uses SeisComP3 software for auto-location of earthquake parameters (location, magnitude, focal depth and origin time). All earthquakes of Mw >5.0 are auto-located within 5–10 minutes of the occurrence of the earthquake. Since its inception in October 2007 to date, the warning centre has monitored and reported 55 tsunamigenic earthquakes (under-sea and near coast earthquakes of magnitude ⩾6.5) in the Indian Ocean region. Comparison of the earthquake parameters (elapsed time, magnitude, focal depth and location) estimated by the Indian Tsunami Early Warning System with the US Geological Survey suggests that the Indian Tsunami Early Warning System is performing well and has achieved the target set up by the Intergovernmental Oceanographic Commission.

Tiny Accelerometers Create Europe's First Urban Seismic Network

The system, under development in Acireale, Italy, could be used to monitor earthquakes in real time and help rescue workers focus efforts where they’re needed most.

Integrated system for site-specific earthquake hazard assessment with geotechnical spatial grid information based on GIS

An integrated earthquake hazard assessment system with geotechnical spatial grid information was developed based on a geographic information system (GIS). The developed system, built, within the frame of GIS, consists of a database (DB) containing all available site information and processed data in the standard formats, and system software that performs various functions to manage and utilize the data in the DB. The system software is divided functionally into an input module, a geostatistical three-dimensional integration module, a real-time earthquake hazard assessment module, and an output or visualization module. A systematic framework for construction of a geotechnical spatial grid was developed to consider local site response characteristics for target areas. According to the framework, three interrelated assessment procedures were incorporated into the DB on a real-time basis: real-time seismic load determination, real-time liquefaction hazard estimation, and real-time structure fragility evaluation. The DB and these sub-modules of the system software were combined and integrated into a single system to provide a familiar and user-friendly working environment with a standard interface. In addition, the integrated system was imbedded into the Korea Integrated Seismic System server to be linked with real-time seismic accelerations, and a simulation of the system was specifically conducted at Incheon Port, Korea, using two actual earthquake events (the 2013 Baengnyeong and 2014 Taean earthquakes) and one virtual earthquake scenario. The simulation results were visualized as a geotechnical earthquake hazard map to verify the computer-aided real-time assessment framework at the times, when the three notable earthquake events occurred at the nearby Incheon Port.

Real time earthquake hazard map of liquefaction in Korea

Real time earthquake hazard map of liquefaction in Korea

Varenna workshop report. Operational earthquake forecasting and decision making

A workshop on <em>Operational earthquake forecasting and decision making</em> was convened in Varenna, Italy, on June 8-11, 2014, under the sponsorship of the EU FP 7 REAKT (Strategies and tools for Real-time EArthquake risK reducTion) project, the Seismic Hazard Center at the Istituto Nazionale di Geofisica e Vulcanologia (INGV), and the Southern California Earthquake Center (SCEC). The main goal was to survey the interdisciplinary issues of operational earthquake forecasting (OEF), including the problems that OEF raises for decision making and risk communication. The workshop was attended by 64 researchers from universities, research centers, and governmental institutions in 11 countries. Participants and the workshop agenda are listed in the appendix.<br />The workshop comprised six topical sessions structured around three main themes: the science of operational earthquake forecasting, decision making in a low-probability environment, and communicating hazard and risk. Each topic was introduced by a moderator and surveyed by a few invited speakers, who were then empaneled for an open discussion. The presentations were followed by poster sessions. During a wrap-up session on the last day, the reporters for each topical session summarized the main points that they had gleaned from the talks and open discussions. This report attempts to distill this workshop record into a brief overview of the workshop themes and to describe the range of opinions expressed during the discussions.

Multi-parameter algorithm for Earthquake Early Warning

Earthquake Early Warning (EEW) system is a real-time earthquake damage mitigation system. It detects, analyzes and transmits information of the impending event at the potential user sites. In the present study, an attempt has been made to develop a multi-parameter-based EEW algorithm for accurate and reliable issuance of EEW. In the present study, not only the individual parameters such as maximum predominant period (), average period (τc), peak displacement (Pd), cumulative absolute velocity and root sum of squares cumulative velocity have been used to develop an algorithm but also various combinations have been attempted to issue alarm. The criterion for issuing warning is based on the alarm status of combinations of parameters at nearest four stations within selected epicentral distance of the event. It has been concluded that three parameter preference-based approach provides most efficient results at a time window of 4 s. The data-set for estimating various parameters required for multi-parameter algorithm has been taken from K-NET seismic array (Japan). The algorithm has been validated on the data taken from different regions. Based on the validation carried out using Indian and PEER-NGA database, the results revealed better performance of multi-parametric EEW algorithm.

Performance improvement techniques for geospatial web services in a cyberinfrastructure environment – A case study with a disaster management portal

High population growth, urbanization, and global climate change drive up the frequency of disasters, affecting the safety of people’s lives and property worldwide. Because of the inherent big-data nature of this disaster-related information, the processes of data exchange and transfer among physically distributed locations are increasingly challenging. This paper presents our proposed efficient network transmission model for interoperating heterogeneous geospatial data in a cyberinfrastructure environment. This transmission model supports multiple data encoding methods, such as GML (Geography Markup Language) and GeoJSON, as well as data compression/decompression techniques, including LZMA and DEFLATE. Our goal is to tackle fundamental performance issues that impact efficient retrieval of remote data. Systematic experiments were conducted to demonstrate the superiority of the proposed transmission model over the traditional OGC Web Feature Service (WFS) transmission model. The experiments also identified the optimized configuration for data encoding and compression techniques in different network environments. To represent a real-world user request scenario, the Amazon EC2 cloud platform was utilized to deploy multiple client nodes for the experiments. A web portal was developed to integrate the real-time geospatial web services reporting with real-time earthquake related information for spatial policy analysis and collaborative decision-making.

Special Issue on Enhancement of Earthquake and Volcano Monitoring and Effective Utilization of Disaster Mitigation Information in the Philippines

Special Issue on Enhancement of Earthquake and Volcano Monitoring and Effective Utilization of Disaster Mitigation Information in the Philippines

High-Rate GPS Seismology Using Real-Time Precise Point Positioning With Ambiguity Resolution

With the availability of real-time high-rate GPS observations and precise satellite orbit and clock products, the interest in the real-time precise point positioning (PPP) technique has greatly increased to construct displacement waveforms and to invert for source parameters of earthquakes in real time. Furthermore, PPP ambiguity resolution approaches, developed in the recent years, overcome the accuracy limitation of the standard PPP float solution and achieve comparable accuracy with relative positioning. In this paper, we introduce the real-time PPP service system and the key techniques for real-time PPP ambiguity resolution. We assess the performance of the ambiguity-fixed PPP in real-time scenarios and confirm that positioning accuracy in terms of root mean square of 1.0–1.5 cm can be achieved in horizontal components. For the 2011 Tohoku-Oki (Japan) and the 2010 El Mayor–Cucapah (Mexico) earthquakes, the displacement waveforms estimated from ambiguity-fixed PPP and those provided by the accelerometer instrumentation are consistent in the dynamic component within few centimeters. The PPP fixed solution not only can improve the accuracy of coseismic displacements but also provides a reliable recovery of earthquake magnitude and of the fault slip distribution in real time.

RTQUAKE, A Real-Time Earthquake Detection System Integrated with SEISAN

Seismic networks have over the last 10–15 years become nearly exclusively real‐time networks. The software used for data collection is both commercial and largely public domain. The two main public domain real‐time detection systems are Earth Worm (EW; Johnson et al. , 1995; http://www.earthwormcentral.org; last accessed March 2014) and SeisComP3 (SC3; www.seiscomp3.org). Both systems receive data in real time, perform triggering, store data in a continuous manner, and automatically determine location and magnitude. For a comparison and evaluation of the two systems, see Olivieri and Clinton (2012). EW and SC3 read data sources using different communication protocols. However, the SeedLink protocol for data exchange, used with SC3, has more or less become the public domain standard for real‐time data transmission due to its simplicity and reliability, and many instrument manufacturers now offer SeedLink as a standard for their seismic field stations. Although both systems provide some degree of automatic processing (SC3 has rather sophisticated automatic location and magnitude ability), most seismic networks would want to do manual processing of some or all of the detected events. Many users transfer the data to the SEISAN processing system (Havskov and Ottemoller, 1999). SEISAN is probably one of the most complete and widely used public domain processing systems available. In 2011, 27% of the agencies reporting to the ISC used SEISAN and reported in SEISAN format (Dmitry Storchak, personal comm., 2011). SEISAN can also work directly with the SC3 archive making this a simple way to inspect, process, and extract data from SC3. We have developed a simple data acquisition system, RTQUAKE, which fully integrates with SEISAN. Its main function is to read real‐time data from SeedLink servers, do triggering of events, and store data in the SEISAN database. Some optional automatic processing can also be done. RTQUAKE works with the …

The Remote Real-Time Earthquake Monitoring System of Isolated Structure Based in NI cRIO

The system monitors seismic responses of isolated structure and non-isolated structure in WenChuan with earthquake, and compared with them. The system of seismic sensors collected seismic signals to the FPGA chip, and FPGA transmits the signal to the real-time controller through the internal bus after filtering. The real-time controller monitors signals and triggers the storage, at the same time the controller will transmit data to the host computer through the Ethernet, and the PC as the local server, which can be accessed real-time by remote computers. A plurality of acquisition station support multiple acquisition station synchronization acquisition using the GPS trigger synchronization.

Real Time Seismic Monitoring System for Earthquake Using GPS Technology

As part of earthquake process, earth's surface is being deformed as earthquake faults accumulate strain & slip or slowly creep over time. We use GPS to monitor this movement by measuring precise position (within 5mm or less) of stations near active faults relative to each other. In this paper, seismic monitoring is made through a real time analysis using GPS technology. This paper explains how GPS will be used to measure the movement of the earth, i.e., how far the earth actually moved & in what direction, this may be in form of lateral movement or vertical displacement. Here GPS enables direct fault motion measurement in earthquake using one or more GPS's three basic components, i.e. absolute location, relative movement & time transfer. The technology here uses real time GPS information to measure vital stats on a quake. The technology use is referred as, Real Time Earthquake Analysis For Disaster, (READI). Because of its accuracy & precision, the technology has played a vital role in sensing the area precised to 5mm. We here are using the GPS data automatically to calculate the location, magnitude & other details about the earthquake fault. GPS receiver is vital component in are paper because it is stationed to receive the satellite's signal, so that movement could be measured with pinpoint accuracy. It will also measure the high frequency carrier wave used to send the code. Its accuracy is lot higher, providing more precise positional information.

Rapid Estimation of Damage to Tall Buildings Using Near Real-Time Earthquake and Archived Structural Simulations

This article outlines a new approach to rapidly estimate the damage to tall buildings immediately following a large earthquake. The preevent groundwork involves the creation of a database of structural responses to a suite of idealized ground‐motion waveforms. The postevent action involves (1) rapid generation of an earthquake source model, (2) near real‐time simulation of the earthquake using a regional spectral‐element model of the earth and computing synthetic seismograms at tall building sites, and (3) estimation of tall building response (and damage) by determining the best‐fitting idealized waveforms to the synthetically generated ground motion at the site and directly extracting structural response metrics from the database. Here, ground‐velocity waveforms are parameterized using sawtoothlike wave trains with a characteristic period (T), amplitude (peak ground velocity, PGV), and duration (number of cycles, N). The proof‐of‐concept is established using the case study of one tall building model. Nonlinear analyses are performed on the model subjected to the idealized wave trains, with T varying from 0.5 s to 6.0 s, PGV varying from 0.125 m/s, and N varying from 1 to 5. Databases of peak transient and residual interstory drift ratios (IDR), and permanent roof drift are created. We demonstrate the effectiveness of the rapid response approach by applying it to synthetic waveforms from a simulated 1857‐like magnitude 7.9 San Andreas earthquake. The peak IDR, a key measure of structural performance, is predicted well enough for emergency response decision making.

Effects of soil nonlinearity and liquefaction on seismic response of pile groups

<p>The seismic behavior of pile groups is very complicated if piles are passing through liquefiable soil. In this paper, the effects of soil nonlinearity and liquefaction on seismic response of pile groups are investigated. A three-dimensional finite element soil-pile model was developed with Kelvin elements for simulating radiation conditions at infinity. The effect of soil nonlinearity was investigated considering work-hardening plastic cap model for the soil. The liquefaction of the soil medium was simulated using two parameter volume change model.</p><p>Seismic responses of a single pile and pile groups were examined considering soil nonlinearity and liquefaction. The study was performed for range of frequency of excitation. Finally analysis is carried out for real time earthquake motion. A significant effect of soil nonlinearity and liquefaction of the soil medium on the seismic response of pile groups was observed and it was also noticed that this effect is very much dependent on peak ground acceleration and frequency characteristics of the input motion.</p>

Real‐time inversion of GPS data for finite fault modeling and rapid hazard assessment

Responses to recent great earthquakes and ensuing tsunamis in Sumatra, Chile, and Japan, with the resulting loss of life and damage to infrastructure demonstrate that our ability to ascertain the full extent of slip of catastrophic earthquakes and their tsunamigenic potential in the first minutes after the initiation of rupture is problematic. Regional GPS networks such as those in western North America and Japan are complementary to seismic networks by being able to directly measure displacements close to the source during large earthquakes in real time. We report on rapid modeling of two large earthquakes, the 2003 Mw 8.3 Tokachi‐oki earthquake 100 km offshore Hokkaido Island using 356 GEONET stations and the 2010 Mw 7.2 El Mayor‐Cucapah earthquake in northern Baja California using 95 CRTN stations in southern California about 75 km northwest of the epicenter. Working in a simulated real‐time mode, we invert for finite fault slip in a homogeneous elastic half‐space using Green's functions obtained from Okada's formulation. We compare two approaches: the first starts with a catalog of pre‐defined faults, while the second uses a rapid centroid moment tensor solution to provide an initial estimate of the ruptured fault plane. In either case, we are able to characterize both earthquakes in less than two minutes, reducing the time necessary to obtain finite fault slip and moment magnitude for medium and greater earthquakes compared to traditional methods by an order of magnitude.

Intensity attenuation for active crustal regions

We develop globally applicable macroseismic intensity prediction equations (IPEs) for earthquakes of moment magnitude MW 5.0–7.9 and intensities of degree II and greater for distances less than 300 km for active crustal regions. The IPEs are developed for two distance metrics: closest distance to rupture (Rrup) and hypocentral distance (Rhyp). The key objective for developing the model based on hypocentral distance—in addition to more rigorous and standard measure Rrup—is to provide an IPE which can be used in near real-time earthquake response systems for earthquakes anywhere in the world, where information regarding the rupture dimensions of a fault may not be known in the immediate aftermath of the event. We observe that our models, particularly the model for the Rrup distance metric, generally have low median residuals with magnitude and distance. In particular, we address whether the direct use of IPEs leads to a reduction in overall uncertainties when compared with methods which use a combination of ground-motion prediction equations and ground motion to intensity conversion equations. Finally, using topographic gradient as a proxy and median model predictions, we derive intensity-based site amplification factors. These factors lead to a small reduction of residuals at shallow gradients at strong shaking levels. However, the overall effect on total median residuals is relatively small. This is in part due to the observation that the median site condition for intensity observations used to develop these IPEs is approximately near the National Earthquake Hazard Reduction Program CD site-class boundary.

Study on the Forecast of Ground Motion Parameters from Real Time Earthquake Information Based on Wave Form Data at the Front Site

Study on the Forecast of Ground Motion Parameters from Real Time Earthquake Information Based on Wave Form Data at the Front Site