Over the last few decades, considerable research into earthquake sources and the hazards they pose have greatly improved our understanding of both. Increases in the quality and quantity of data recorded, combined with the development of new analysis techniques, have resulted in significantly better models of the earthquake rupture process. These in turn have permitted more reliable statistical seismic hazard predictions. Despite this progress, many fundamental questions concerning earthquake rupture and fault processes remain unanswered, and others have been identified as we learn more about them.
Thematic Working Groups
TWG Structures and Tasks Complete TWG Member List TWG Online Community
External Map Resources
USGS Digital State Geologic Maps
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Visualizations
Many research facilities are using EarthScope instrument data to produce scientific models and visual representations.
SIO Visualization Center
EarthScope Voyager, Jr.
UC Davis KeckCAVES
Faults and Earthquake Processes
EarthScope is aiding in the development predictive models for earthquakes by unraveling the dynamic processes along faults, from stress build-up to catastrophic rock failure. Additionally, EarthScope is enabling us to observe the processes and properties of faults that drive the earthquake machine.
Contemporary seismic hazard maps of the United States demonstrate clearly that California is not the only state to experience or expect large earthquakes. PBO and USArray are greatly improving our understanding of earthquake processes along the Cascadia and Alaskan subduction zones. USArray and InSAR/LiDAR are providing us with unprecedented resolution and information about the eastern half of the United States, where large damaging earthquakes can occur. Figures courtesy of the USGS.
Research Questions
- How does strain accumulate and release at plate boundaries and within the North American plate?
- How do earthquakes start, rupture, and stop?
- What is the absolute strength of faults and the surrounding lithosphere?
- What structural and geologic factors give rise to intraplate regions seismicity?
- How can we accurately predict earthquake induced ground motions over a wide frequency range?
Implications of EarthScope
Recent work has demonstrated that only an order of magnitude improvement in data quality and quantity are permitting us to address the outstanding scientific questions about earthquake processes with any realistic hope of success. The combined EarthScope components are providing much of the data required to significantly increase our understanding of the entire earthquake rupture process. For example, previous work has demonstrated that large earthquakes nucleate as a result of processes acting at a very small scale that currently cannot be resolved.
