ShakeMap

ShakeMap
Awaldy · CC BY-SA 4.0 · source
Name	ShakeMap
Developer	United States Geological Survey
Initial release	1990s
Latest release	ongoing
Programming language	C++, Python
Platform	Linux, Windows
Genre	Seismic intensity mapping

ShakeMap is a digital seismic intensity mapping system designed to produce near–real-time representations of ground shaking following earthquakes. Developed to translate seismic source information into spatial estimates of shaking severity, it supports decision-making by linking instrumental data with built environment concerns, infrastructure, and humanitarian needs. ShakeMap outputs integrate seismic instrumentation, geodetic observations, and empirical ground‑motion models to produce maps used by first responders, engineers, insurers, and researchers.

Overview

ShakeMap generates spatially continuous depictions of ground shaking intensity and related measures such as peak ground acceleration and spectral acceleration. The system ingests inputs from networks like the Global Seismographic Network, regional agencies such as the California Integrated Seismic Network and the Japan Meteorological Agency, and combines them with models developed by consortia including the Pacific Earthquake Engineering Research Center and the Global Earthquake Model. ShakeMap products are consumed by organizations including the Federal Emergency Management Agency, European-Mediterranean Seismological Centre, Red Cross, World Bank, and engineering firms working on FEMA P-58 assessments.

History and Development

ShakeMap originated within the United States Geological Survey during the 1990s as part of initiatives following significant events like the 1994 Northridge earthquake and the 1989 Loma Prieta earthquake. Early development involved partnerships with academic institutions such as the California Institute of Technology and the University of California, Berkeley and incorporated insights from major investigations including the 1995 Kobe earthquake reconnaissance. Over time, ShakeMap integrated advances from projects including the Seismic Hazard Analysis efforts, improvements in the Global Positioning System processing by agencies like NOAA, and earthquake cataloging from the International Seismological Centre.

Methodology and Data Inputs

ShakeMap combines seismic phase picks, waveform data, and geodetic offsets with ground‑motion prediction equations developed by groups such as the Next Generation Attenuation (NGA) project and empirical models from the Pacific Earthquake Engineering Research Center. Instrumental inputs originate from arrays operated by entities like the USArray, regional networks such as the Southern California Seismic Network, and global stations in the Global Seismographic Network. The system uses site condition proxies including the United States Geological Survey's Vs30 models, geologic maps from the United States Geological Survey National Geologic Map Database, and population density layers from the United Nations databases to weight exposure. ShakeMap processing pipelines employ software libraries common to the seismological community such as ObsPy and tools developed at institutions like Lamont–Doherty Earth Observatory.

Product Types and Outputs

ShakeMap produces a suite of products: spatial grids of intensity measures (Modified Mercalli Intensity equivalents), peak ground acceleration and velocity, spectral acceleration at engineering periods used in ASCE/SEI standards, and uncertainty bounds. Outputs include GIS‑ready rasters, contour maps, and annotated PDFs for distribution to agencies like FEMA and the European Commission's Civil Protection Mechanism. Derived layers such as estimated population exposure and impact estimates are prepared for stakeholders including World Health Organization planners and the International Federation of Red Cross and Red Crescent Societies.

Applications and Use in Emergency Response

Emergency managers in agencies like FEMA, California Office of Emergency Services, and municipal authorities use ShakeMap to prioritize reconnaissance, route critical infrastructure inspections for utilities such as Pacific Gas and Electric Company, and trigger building safety evaluations following standards from ASCE. Humanitarian organizations including the International Red Cross and the United Nations Office for the Coordination of Humanitarian Affairs use ShakeMap exposure estimates to allocate relief. Insurers and reinsurers refer to ShakeMap ground‑motion fields when activating catastrophe models used by firms such as Swiss Re and Munich Re.

Limitations and Validation Studies

ShakeMap’s accuracy depends on station density, the representativeness of ground‑motion prediction equations, and site amplification models; sparse networks in regions overseen by agencies like the National Oceanic and Atmospheric Administration can increase uncertainty. Validation studies by academic groups at Stanford University, University of California, Los Angeles, and ETH Zurich compare ShakeMap outputs to field observations from events including the 2011 Tōhoku earthquake and tsunami and the 1999 İzmit earthquake, highlighting biases in complex basin settings and near‑fault rupture directivity. Ongoing research integrates geodetic inversions, finite‑fault models from teams at Scripps Institution of Oceanography, and machine‑learning approaches spearheaded by centers such as Oak Ridge National Laboratory to reduce uncertainties.

Implementation and Global Use

ShakeMap infrastructure has been adapted and implemented by national agencies including the Japan Meteorological Agency, the Instituto Geofísico del Perú, the Geological Survey of Canada, and regional centers like the European-Mediterranean Seismological Centre. International capacity‑building programs run jointly with organizations such as the World Bank and the United Nations Development Programme have promoted adoption in countries affected by seismic risk, including partners in Chile, Nepal, Turkey, and Indonesia. Academic collaborations continue through consortia like the Global Earthquake Model to standardize products and integrate ShakeMap outputs into global loss‑estimation frameworks used by OECD stakeholders.

Category:Seismology