Prompt Assessment Of Global Earthquakes Research Articles

The Potential of Crowdsourced Data for the Rapid Impact Assessment of Large Earthquakes: The 2023 M 7.8 Kahramanmaraş-Pazarcık, Türkiye, Earthquake

Abstract Reliable and rapid impact assessment for large earthquakes is a challenge because it is difficult to rapidly determine the fault geometry and thus the spatial distribution of shaking intensities. In this retrospective study of the M 7.8 Kahramanmaraş-Pazarcık, Türkiye, earthquake, we evaluate how eyewitness observations crowdsourced through the LastQuake system can improve such assessments. These data consist of felt reports describing the local level of shaking or damage and manually validated geolocated imagery. In the first part of this study, the methods used to derive macroseismic intensity values from felt reports, particularly for high values, are validated by comparison with independently determined intensities. This comparison confirms that the maximum intensity that can be derived from felt reports does not generally exceed VIII. A fatality estimate of 3000 could be made within a few hours by evaluating the number of people exposed to high intensities using the felt reports and assuming a point source. However, this estimate was known to be an underestimate because of the point-source approximation; this underestimate was also confirmed by the geolocated imagery showing high levels of damage at epicentral distances well beyond those predicted by circular isoseismals. However, improved estimates could have been derived from the event’s ShakeMaps using the U.S. Geological Survey Prompt Assessment of Global Earthquakes for Response (PAGER) fatality loss-modeling system, either by incorporating the felt reports into the ShakeMaps computation or using, in addition, a finite-source (here line-source) model derived from the felt reports using the Finite-fault rupture Detector software. The inclusion of fault geometry would have resulted in a fatality estimate with data collected within 10 min of the origin determination, which was consistent with the final PAGER alert level and the reported death toll that were both only known days later. Although more work would be helpful to assess the reliability of the derived fault geometry, in regions where they are collected in large numbers, felt reports collected within 10 min of the earthquake can be used to substantially improve current fatality estimates.

Assessment of the General Public’s Understanding of Rapidly Produced Earthquake Information Products ShakeMap and PAGER

Abstract Public engagement through outreach is a key mechanism for learning about science and to communicate societal impacts of government-funded science. However, outreach effectiveness could be limited if approaches are not evidenced based. Partnerships with cognitive scientists who study fundamental learning processes suggest helping people learn how earthquakes happen would improve understanding of hazards and motivation for preparedness. We used a seismology–cognitive science partnership to evaluate understanding by nongeoscientists of widely viewed U.S. Geological Survey (USGS) ShakeMap and Prompt Assessment of Global Earthquakes for Response (PAGER) products originally developed for technical use. After discussions with USGS staff, we constructed 13 free response questions probing understanding of these products, including the graph literacy scale (GLS) for comparison. Through Zoom interviews of 101 participants, we found poor performance (28% correct) on the PAGER and ShakeMap questions despite good performance (76% correct) on the GLS. When coding free responses, we identified an average of 12.4 misconceptions per participant, approximately 1 per question. Five misconceptions were observed in over half the participants, including how the reports are constructed and used in real time, treating reports using modeling or simulations as containing only direct observations, and difficulty interpreting probabilities. The performance and misconceptions led us to develop a revised PAGER with scatter plots to visualize fatality and damage probabilities among other simplifications. We used a multiple-choice survey to assess understanding using the original and new visualizations with another 100 participants. We found significant improvement: 49% correct when seeing the revised visualization first, compared with 36% when seeing the original visualization first. Finally, we surveyed 147 participants on whether they could distinguish expert-defined shaking and damage descriptors for three macroseismic terms (moderate, strong, and severe). Participants struggled, choosing greater consequences than intended for lower intensity terms. Overall, our findings suggest that the key aspects of these earthquake information products are poorly understood by nongeoscientists in aseismic regions, but adjustments can improve effectiveness.

ESTIMATING ECONOMIC LOSSES FROM SINABANG EARTHQUAKE USING AN EMPIRICAL APPROACH

The empirical approach is a potential candidate along with other engineering-based loss models within the Prompt Assessment of Global Earthquakes for Response (PAGER) system for rapid social and economic loss estimation. In this study, we focused to evaluate the Sinabang earthquake on 7 January 2020 with Magnitude 6.3. The result of this study shown the green alert for shaking related fatalities and economic losses in 65 % from the estimated fatalities and losses in Sinabang.

Estimating Economic Losses From Sinabang Earthquake Using An Empirical Approach

The empirical approach is a potential candidate along with other engineering-based loss models within the Prompt Assessment of Global Earthquakes for Response (PAGER) system for rapid social and economic loss estimation. In this study, we focused to evaluate the Sinabang earthquake on 7 January 2020 with Magnitude 6.3. The result of this study shown the green alert for shaking related fatalities and economic losses in 65 % from the estimated fatalities and losses in Sinabang.

An efficient Bayesian framework for updating PAGER loss estimates

We introduce a Bayesian framework for incorporating time-varying noisy reported data on damage and loss information to update near real-time loss estimates/alerts for the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) system. Initial loss estimation by PAGER immediately following an earthquake includes several uncertainties. Historically, the PAGER’s alerting on fatality and economic losses has not incorporated location-specific reported data on physical damage or casualties for a given earthquake. The proposed framework provides the ability to include early reports on fatalities at any given time and improve the overall impact forecast for the earthquake. The reported data on fatalities or damage are generally incomplete and noisy, especially in the early hours of the disaster. To address these challenges, we develop a recursive Bayesian updating framework that takes into account the loss projection model and the measurement and model uncertainties. The framework is applied to loss data for three example earthquakes, and the results show that the proposed updating improves the loss estimates and alert level to the correct level within the first day of the earthquake.

A domestic earthquake impact alert protocol based on the combined USGS PAGER and FEMA Hazus loss estimation systems

The United States Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) alert system provides rapid (10–20 min) but general loss estimates of ranges of fatalities and economic impact for significant global earthquakes. FEMA’s Hazus software, in contrast, provides time-consuming (2–5 h) but more detailed loss information quantified in terms of structural, social, and economic consequences estimated at a much higher spatial resolution for large domestic earthquakes. We developed a rapid hybrid post-earthquake product that takes advantage of the best of both loss models. First, though, we conducted a systematic comparison of loss estimates from PAGER with Hazus for all significant, relatively recent, domestic earthquakes for which adequate loss data exist—augmented by a dozen ShakeMap scenarios. The systematic comparison of Hazus and PAGER losses provided the basis for selecting the specific loss metrics to present from each system. The signature product will serve as a supplement to the widely deployed PAGER alert product for significant domestic earthquakes.

Rapid estimation of earthquake fatalities in China using an empirical regression method

This article provides a random coefficient model for anticipating the occurrence trend of earthquake fatalities and rapidly estimating the number earthquake fatalities in China. We then predicted the number of earthquake deaths in China using 206 earthquake records from 1900 to 2016 and basing our predictions on the empirical regression method in the Prompt Assessment of Global Earthquakes for Response (PAGER) system. In general, half the total fatalities are usually certified in the first 23 h after an earthquake; 80% of all certified of an earthquake are usually certified in the first 77 h after an incident, and usually 164 h after an incident 99% of the total deaths are certified and the death toll tends to stabilize. A greater magnitude for an earthquake results in a longer duration for the rapid growth period, and a longer time is needed for the total number of deaths to stabilize. The fatalities in Wenchuan and Yushu earthquake calculated by our prediction model were 67,704 and 2,657, close to the actual fatalities of 69,227 and 2,698, respectively. Our dynamic estimation model to simulate death occurrence in changing environments can quickly estimate the earthquake death totals in Chinese earthquakes and accurately define the earthquake scale to facilitate post-earthquake emergency rescue.

A building classification scheme of housing stock in Malawi for earthquake risk assessment

This study presents a building classification scheme for residential houses in Malawi by focusing upon informal construction, which accounts for more than 90% of housing in the country with the highest urbanisation rate in the world. The proposed classification is compatible with the Prompt Assessment of Global Earthquakes for Response (PAGER) method and can be used for seismic vulnerability assessments of building stock in Malawi. To obtain realistic proportions of the building classes that are prevalent in Malawi, a building survey was conducted in Central and Southern Malawi between 10th and 20th July 2017. The results from the survey are used to modify the PAGER-based proportions of main housing typologies by reflecting actual housing construction in the surveyed areas. The results clearly highlight the importance of using realistic building stock data for seismic risk assessment in Malawi; relying on global building stock information can result in significant bias of earthquake impact assessment.

Rapid detection of earthquake damage areas using VIIRS nearly constant contrast night-time light data

ABSTRACTTo rapidly identify earthquake damage areas after earthquakes occur, a method based on Visible Infrared Imaging Radiometer Suite (VIIRS) night-time light (NTL) images with nearly constant contrast (NCC) is proposed. The differences between post-earthquake and mean image of 3 months VIIRS NCC NTL before an earthquake are taken to reflect the effects of earthquakes on city light brightness loss, with eliminating the influence of clouds, lunar and solar irradiance, and poor-quality NCC NTL pixels. In addition, the standard deviation (STD) of the NTL images collected during the 3 months before an earthquake is calculated. Then, the areas with the differences less than −1 times the local STD are taken to be earthquake damage areas, and the areas with differences less than −2 times the local STD are taken to be severely damage areas. Finally, this method is applied to the 2015 Nepal moment magnitude (Mw) 7.8 earthquake, the 2014 Chile Mw 8.1 earthquake, and the 2015 Chile Mw 8.3 earthquake. Compared with Prompt Assessment of Global Earthquakes for Response output for selected cities impacted by these earthquakes, the results show that the overall accuracies are 14.9%, 75.0%, and 68.4% respectively, for the three earthquakes with the accuracy increases with greater earthquake intensities.

Estimating Economic Losses from Earthquakes Using an Empirical Approach

We extended the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) empirical fatality estimation methodology proposed by Jaiswal et al. (2009) to rapidly estimate economic losses after significant earthquakes worldwide. The requisite model inputs are shaking intensity estimates made by the ShakeMap system, the spatial distribution of population available from the LandScan database, modern and historic country or sub-country population and Gross Domestic Product (GDP) data, and economic loss data from Munich Re's historical earthquakes catalog. We developed a strategy to approximately scale GDP-based economic exposure for historical and recent earthquakes in order to estimate economic losses. The process consists of using a country-specific multiplicative factor to accommodate the disparity between economic exposure and the annual per capita GDP, and it has proven successful in hindcast-ing past losses. Although loss, population, shaking estimates, and economic data used in the calibration process are uncertain, approximate ranges of losses can be estimated for the primary purpose of gauging the overall scope of the disaster and coordinating response. The proposed methodology is both indirect and approximate and is thus best suited as a rapid loss estimation model for applications like the PAGER system.

Monitoring the Earthquake Source Process in North America

With the implementation of the USGS National Earthquake Information Center Prompt Assessment of Global Earthquakes for Response system (PAGER), rapid determination of earthquake moment magnitude is essential, especially for earthquakes that are felt within the contiguous United States. We report an implementation of moment tensor processing for application to broad, seismically active areas of North America. This effort focuses on the selection of regional crustal velocity models, codification of data quality tests, and the development of procedures for rapid computation of the seismic moment tensor. We systematically apply these techniques to earthquakes with reported magnitude greater than 3.5 in continental North America that are not associated with a tectonic plate boundary. Using the 0.02–0.10 Hz passband, we can usually determine, with few exceptions, moment tensor solutions for earthquakes with M w as small as 3.7. The threshold is significantly influenced by the density of stations, the location of the earthquake relative to the seismic stations and, of course, the signal-to-noise ratio. With the existing permanent broadband stations in North America operated for rapid earthquake response, the seismic moment tensor of most earthquakes that are M w 4 or larger can be routinely computed. As expected the nonuniform spatial pattern of these solutions reflects the seismicity pattern. However, the orientation of the direction of maximum compressive stress and the predominant style of faulting is spatially coherent across large regions of the continent.

Developing Empirical Collapse Fragility Functions for Global Building Types

Building collapse is the dominant cause of casualties during earthquakes. In order to better predict human fatalities, the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) program requires collapse fragility functions for global building types. The collapse fragility is expressed as the probability of collapse at discrete levels of the input hazard defined in terms of macroseismic intensity. This article provides a simple procedure for quantifying collapse fragility using vulnerability criteria based on the European Macroseismic Scale (1998) for selected European building types. In addition, the collapse fragility functions are developed for global building types by fitting the beta distribution to the multiple experts’ estimates for the same building type (obtained from EERI's World Housing Encyclopedia (WHE)-PAGER survey). Finally, using the collapse probability distributions at each shaking intensity level as a prior and field-based collapse-rate observations as likelihood, it is possible to update the collapse fragility functions for global building types using the Bayesian procedure.

Rapid Simulation of Seismic Intensity for Civil Protection Purposes: Two Recent Cases in Italy

After a destructive earthquake, civil protection agencies need to know within a matter of minutes where people who are buried alive by rubble can be found. Moreover, they must also be informed as soon as possible—in a matter of hours—about the scope of the disaster, in order to organize rescue teams, provide emergency aid, set up field hospitals and tents for the homeless or displaced, etc. In addition, a financial estimate of damage must be made available to the government. Finally, fast and easily presentable information must be provided to the world at large; ShakeMap (Wald et al. 1999; Wald et al. 2006) and the Prompt Assessment of Global Earthquakes for Response (PAGER; Earle and Wald 2007) accomplish this task. Governing bodies, and also some experts, end up hoping that these calculation products can provide, in almost real time, results that are so detailed they can even be used for the instant needs of civil protection. In other words, in these times of virtual reality, some people hope that the very first rescue teams and other forms of aid can be sent automatically, based on the coordinates of where the model has predicted the worst damage. Now it is true that there has been an impressive increase in seismic networks and in our ability to produce damage scenarios, but unfortunately, no algorithm has the ability to make virtual reality coincide with true reality. In fact, certain losses are also due to factors not predictable by a model (see Discussion and Conclusions). In this work, we investigate the potentialities and limitations of three types of scenarios, produced after the occurrence of two Italian earthquakes of M 5.2 and 6.3. Five out of six scenarios were of acceptable quality for providing generic information to the public; no scenario was sufficient for …

An Empirical Model for Global Earthquake Fatality Estimation

We analyzed mortality rates of earthquakes worldwide and developed a country/region-specific empirical model for earthquake fatality estimation within the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) system. The earthquake fatality rate is defined as total killed divided by total population exposed at specific shaking intensity level. The total fatalities for a given earthquake are estimated by multiplying the number of people exposed at each shaking intensity level by the fatality rates for that level and then summing them at all relevant shaking intensities. The fatality rate is expressed in terms of a two-parameter lognormal cumulative distribution function of shaking intensity. The parameters are obtained for each country or a region by minimizing the residual error in hindcasting the total shaking-related deaths from earthquakes recorded between 1973 and 2007. A new global regionalization scheme is used to combine the fatality data across different countries with similar vulnerability traits.

A Global Building Inventory for Earthquake Loss Estimation and Risk Management

We develop a global database of building inventories using taxonomy of global building types for use in near-real-time post-earthquake loss estimation and pre-earthquake risk analysis, for the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) program. The database is available for public use, subject to peer review, scrutiny, and open enhancement. On a country-by-country level, it contains estimates of the distribution of building types categorized by material, lateral force resisting system, and occupancy type (residential or nonresidential, urban or rural). The database draws on and harmonizes numerous sources: (1) UN statistics, (2) UN Habitat's demographic and health survey (DHS) database, (3) national housing censuses, (4) the World Housing Encyclopedia and (5) other literature.

Development of Earthquake Lossmap for Europe

For almost real-time estimation of the losses after a major earthquake in the Euro-Mediterranean region, the Joint Research Area-3 (JRA-3) component of the European Union (EU) Project “Network of Research Infrastructures for European Seismology – NERIES” foresees (at several levels of sophistication): 1. Finding the most likely location of the source of the earthquake using regional seismotectonic data base; 2. estimation of the spatial distribution of selected site-specific ground motion parameters; 3. correlation/verifyication/enrichment of the estimated ground shaking information with the available on-line strong motion data; and 4. estimation of physical damage and casualty distributions. These LossMaps will provide the required vital information within minutes after an earthquake to European emergency response agencies, in a manner similar to the United States Geological Survey (USGS)'s Prompt Assessment of Global Earthquakes for Response (PAGER) system. A methodology that incorporates the regional dependencies and sources of uncertainty stemming from ground motion predictions, fault finiteness, site modifications, inventory of elements subjected to the hazard, and the vulnerability relationships is under preparation with researchers from Imperial College, NORSAR and ETH-Zurich. A pilot application is established for Turkey that encompasses the gridded earthquake source, Quaternary, Tertiary, Mesozoic (QTM) geological classification and physical and demographic inventory mapping for the whole country. Within the scope of this study, loss estimations were computed for the 1999 Kocaeli earthquake using several approaches and comparisons made with observed values. The LossMap tool will be available for the first estimation of damage immediately after an earthquake in Turkey by the end of 2007 and for the whole Euro-Med region by the end of 2009.