Sismotool: A New Tool to Simulate Ground Shaking and Earthquake Losses

2022 ◽  
Author(s):  
Fernando Lopez ◽  
Manuel Navarro ◽  
Sergio Molina
2005 ◽  
Vol 21 (4) ◽  
pp. 1157-1184 ◽  
Author(s):  
Ivan Wong ◽  
Jawhar Bouabid ◽  
William Graf ◽  
Charles Huyck ◽  
Allan Porush ◽  
...  

A comprehensive earthquake loss assessment for the state of South Carolina using HAZUS was performed considering four different earthquake scenarios: a moment magnitude ( M) 7.3 “1886 Charleston-like” earthquake, M 6.3 and M 5.3 events also from the Charleston seismic source, and an M 5.0 earthquake in Columbia. Primary objectives of this study were (1) to generate credible earthquake losses to provide a baseline for coordination, capability development, training, and strategic planning for the South Carolina Emergency Management Division, and (2) to raise public awareness of the significant earthquake risk in the state. Ground shaking, liquefaction, and earthquake-induced landsliding hazards were characterized using region-specific inputs on seismic source, path, and site effects, and ground motion numerical modeling. Default inventory data on buildings and facilities in HAZUS were either substantially enhanced or replaced. Losses were estimated using a high resolution 2- km×2- km grid rather than the census tract approach used in HAZUS. The results of the loss assessment indicate that a future repeat of the 1886 earthquake would be catastrophic, resulting in possibly 900 deaths, more than 44,000 injuries, and a total economic loss of $20 billion in South Carolina alone. Schools, hospitals, fire stations, ordinary buildings, and bridges will suffer significant damage due to the general lack of seismic design in the state. Lesser damage and losses will be sustained in the other earthquake scenarios although even the smallest event could result in significant losses.


2021 ◽  
pp. 875529302110420
Author(s):  
Yajie Lee ◽  
Zhenghui Hui ◽  
Siamak Daneshvaran ◽  
Farhad Sedaghati ◽  
William P Graf

The Uniform California Earthquake Rupture Forecast Version 3 (UCERF3) relaxes fault segmentation, allowing multi-segment and multi-fault ruptures through fault-to-fault “jumps,” with lengths up to ∼1200 km along the San Andreas Fault. Local faults are also highly interconnected, including ruptures on the order of hundreds of kilometers. These prescribed long ruptures did not exist in older models. Longer ruptures produce larger aggregate loss estimates for geographically dispersed assets (portfolios) due to the wider areas that are affected by strong ground shaking. In this study, we model probabilistic earthquake losses of a hypothetical state-wide building portfolio in California. We develop risk deaggregation methods to identify multi-segment and multi-fault ruptures that contribute significantly to high portfolio-wide risks. Three risk measures that are commonly used in risk management decisions are examined: Average Annual Loss (AAL), Return Period Loss (RPLα), and Tail Conditional Expectation (TCEα), for an annual exceedance probability “α,” or corresponding return period “1/α.” Our results show that while the super long ruptures (>500 km) contribute modestly (∼7%) to the portfolio AAL estimate, they contribute more significantly to portfolio catastrophe risk estimates. Specifically, at a 250 year return period, these long ruptures contribute about 26% and 32% to RPL250 and TCE250 estimates, respectively. At a 500-year return period, the corresponding contributions reach about 35% and 39%. Ruptures that connect complex fault systems are also found to be highly influential to estimated portfolio risks. At a 500-year return period, a mere six rupture groups contribute nearly 70% to the RPL500 estimate. Due to the importance of the UCERF3 model to many risk management and public policy decisions, a critical examination of the limit and uncertainty of fault connectivity and rupture lengths of future earthquakes, as well as their impacts on catastrophe risk assessments, is warranted in future model updates.


2021 ◽  
Author(s):  
Fernando López Hidalgo ◽  
Manuel Navarro ◽  
Sergio Molina

Abstract The main purpose of SISMOTOOL suite is Planning and Management of Seismic Emergencies face to a future earthquake. This tool is written in ARCGIS software executing a fast and efficient determination of the estimated damage scenarios (pre-process) and a correlation with the observed damage results (post-process). First of all, the tool allows to select the earthquake source parameters through a defined database; moreover, several attenuation laws can be chosen and they can be combined according to the study area features. In addition, the local site effects are characterized from Vs30 values, which have been achieved by: i) topographic slope as a proxy obtained from Digital Elevation Model; ii) considering Vs30 values acquired from active and/or passive empirical methods; iii) a combination of both procedures through empirical local correlation laws. In the second place, the elements exposed to risk are incorporated by an automatic extraction from the cadastral database after inputs has been refined. Thirdly, vulnerability and estimated losses can be determined either empirically (EMS98 scale and Vulnerability Index, Iv) or analytically (Capacity spectrum). Additionally, a vulnerability modifier is implemented to account soil-structure resonance. Finally, SISMOTOOL quantifies the epistemic uncertainties in the input parameters using a logic tree. Last, but not least, SISMOTOOL results have been validated through a representative seismic scenario: the 1910 Adra earthquake (southern Spain) with moment magnitude (Mw) 6.3 and macroseismic intensity VIII (EMS98 scale) proves the reliability of SISMOTOOL program.


1997 ◽  
Vol 13 (4) ◽  
pp. 703-720 ◽  
Author(s):  
Charles A. Kircher ◽  
Robert K. Reitherman ◽  
Robert V. Whitman ◽  
Christopher Arnold

This paper describes methods for estimating building losses that were developed for the FEMA/NIBS earthquake loss estimation methodology (Whitman et al., 1997). These methods are of a new form and represent a significant step forward in the prediction of earthquake impacts. Unlike previous building loss models that are based on Modified Mercalli Intensity, the new methods use quantitative measures of ground shaking (and ground failure) and analyze model building types in a similar manner to the engineering analysis of a single structure. Direct economic losses predicted by these new methods for typical single-family homes compare well with observed losses to Los Angeles County residences damaged by the 1994 Northridge Earthquake.


2020 ◽  
Vol 14 (4) ◽  
pp. 405-412
Author(s):  
Endra Gunawan ◽  
Takuya Nishimura ◽  
Susilo Susilo ◽  
Sri Widiyantoro ◽  
Nanang T. Puspito ◽  
...  

AbstractOn 6 December 2016 at 22:03 UTC, a devastating magnitude 6-class strike-slip earthquake occurred along an unidentified and unmapped fault in Pidie Jaya, northern Sumatra. We analysed the possible fault using continuous Global Positioning System (GPS) observation available in the region. In our investigation, we searched for the fault source parameters of the north- and south-dipping left-lateral faults and the west- and east-dipping right-lateral faults. We identified that the fault responsible for the earthquake was located offshore, with a southwest-northeast direction. We also computed the Coulomb failure stress and compared the result with the distribution of the aftershocks. In this study, we demonstrated that the result of the geological field survey conducted soon after the mainshock was attributed to the secondary effects of ground shaking and near-surface deformation, and not surface faulting. The newly identified offshore fault proposed by this study calls for further investigation of the corresponding submarine morphological attributes in this particular region.


Author(s):  
Iunio Iervolino ◽  
Pasquale Cito ◽  
Chiara Felicetta ◽  
Giovanni Lanzano ◽  
Antonio Vitale

AbstractShakeMap is the tool to evaluate the ground motion effect of earthquakes in vast areas. It is useful to delimit the zones where the shaking is expected to have been most significant, for civil defense rapid response. From the earthquake engineering point of view, it can be used to infer the seismic actions on the built environment to calibrate vulnerability models or to define the reconstruction policies based on observed damage vs shaking. In the case of long-lasting seismic sequences, it can be useful to develop ShakeMap envelopes, that is, maps of the largest ground intensity among those from the ShakeMap of (selected) events of a seismic sequence, to delimit areas where the effects of the whole sequence have been of structural engineering relevance. This study introduces ShakeMap envelopes and discusses them for the central Italy 2016–2017 seismic sequence. The specific goals of the study are: (i) to compare the envelopes and the ShakeMap of the main events of the sequence to make the case for sequence-based maps; (ii) to quantify the exceedance of design seismic actions based on the envelopes; (iii) to make envelopes available for further studies and the reconstruction planning; (iv) to gather insights on the (repeated) exceedance of design seismic actions at some sites. Results, which include considerations of uncertainty in ShakeMap, show that the sequence caused exceedance of design hazard in thousands of square kilometers. The most relevant effects of the sequence are, as expected, due to the mainshock, yet seismic actions larger than those enforced by the code for structural design are found also around the epicenters of the smaller magnitude events. At some locations, the succession of ground-shaking that has excited structures, provides insights on structural damage accumulation that has likely taken place; something that is not accounted for explicitly in modern seismic design. The envelopes developed are available as supplemental material.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 678
Author(s):  
Mark van der Meijde ◽  
Md Ashrafuzzaman ◽  
Norman Kerle ◽  
Saad Khan ◽  
Harald van der Werff

It remains elusive why there was only weak and limited ground shaking in Kathmandu valley during the 25 April 2015 Mw 7.8 Gorkha, Nepal, earthquake. Our spectral element numerical simulations show that, during this earthquake, surface topography restricted the propagation of seismic energy into the valley. The mountains diverted the incoming seismic wave mostly to the eastern and western margins of the valley. As a result, we find de-amplification of peak ground displacement in most of the valley interior. Modeling of alternative earthquake scenarios of the same magnitude occurring at different locations shows that these will affect the Kathmandu valley much more strongly, up to 2–3 times more, than the 2015 Gorkha earthquake did. This indicates that surface topography contributed to the reduced seismic shaking for this specific earthquake and lessened the earthquake impact within the valley.


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