Subduction Zone Science

Earthquakes

Giant earthquakes occur on giant "megathrust" faults, which comprise the stuck portions of the interface between two converging tectonic plates. Other more frequent smaller earthquakes also occur elsewhere, within the down-going plate or the crust of the upper plate.

Filter Total Items: 20
Date published: September 12, 2018
Status: Active

Significant Earthquakes on a major fault system in Hispaniola, Puerto Rico, the Virgin Islands, and the Lesser Antilles, 1500–2010: Implications for Seismic Hazard

Earthquakes have been documented in the northeastern Caribbean since the arrival of Columbus to the Americas; written accounts of these felt earthquakes exist in various parts of the world.  To better understand the earthquake cycle in the Caribbean, the records of earthquakes in earlier catalogs and historical documents from various archives, which are now available online, were critically...

Date published: August 22, 2018
Status: Active

Caribbean Tsunami and Earthquake Hazards Studies- Models

The Puerto Rico trench exhibits great water depth, extremely low gravity anomaly, and a tilted carbonate platform between (reconstructed) elevations of +1300 m and -4000 m. we suggest that these features are manifestations of large vertical movements of a segment of the Puerto Rico Trench, its forearc, and the island of Puerto Rico that took place 3.3 m.y. ago over a time period as short as 14...

Date published: August 22, 2018
Status: Active

Caribbean Tsunami and Earthquake Hazards Studies- Stress Changes and Earthquake Hazard

Strike-slip faults in the forearc region of a subduction zone often present significant seismic hazard because of their proximity to population centers. We explore the interaction between thrust events on the subduction interface and strike-slip faults within the forearc region using 3-D models of static Coulomb stress change.

  

Date published: August 22, 2018
Status: Active

Caribbean Tsunami and Earthquake Hazards Studies- Seafloor Map

To help understand the origin of the unusual bathymetry, gravity, and vertical tectonics of the plate boundary and to provide constraints for hazard assessment, the morphology of the entire 770-km-long trench from the Dominican Republic in the west to Anguilla in the east was mapped with multibeam echosounder during three cruises in 2002 and 2003. Parts of the Puerto Rico Trench were...

Date published: August 21, 2018
Status: Active

Caribbean Tsunami and Earthquake Hazards Studies

Puerto Rico and the Virgin Islands are located at an active plate boundary between the North American plate and the northeast corner of the Caribbean plate. Plate movements have caused large magnitude earthquakes and devastating tsunamis. The USGS has an ongoing program to identify and map the faults in this region using various geophysical and geological methods in order to estimate the...

Date published: June 5, 2018
Status: Active

Margin-wide geological and geophysical synthesis to understand the recurrence and hazards of great subduction zone earthquakes in Cascadia

The Cascadia Subduction Zone, located in the U.S. Pacific Northwest and southwestern British Columbia, has hosted magnitude ≥8.0 megathrust earthquakes in the geologic past, a future earthquake is imminent, and the potential impacts could cripple the region. Subduction zone earthquakes represent some of the most devastating natural hazards on Earth. Despite substantial knowledge gained from...

Date published: March 20, 2018
Status: Active

Tsunamis

The 2004 Indian Ocean, 2010 Chilean, and 2011 Tohoku disasters have shown how tsunamis are significant threats to coastal communities. To help U.S. coastal communities prepare for future tsunamis, the Hazards Vulnerability Team completed projects related to population exposure and sensitivity, pedestrian evacuation modeling, and vertical-evacuation decision support.

A recent article of...

Date published: March 19, 2018
Status: Active

Hazards Vulnerability Team

Our country faces a wide array of natural hazards that threaten its safety, security, economic well-being, and natural resources. To minimize future losses, communities need a clear understanding of how they are vulnerable to natural hazards and of strategies for increasing their resilience. Vulnerability and resilience are influenced by (1) how communities choose to use hazard-prone land, (2...