Earthquakes and Faults

Our tsunami scientists work on international teams to study the aftermath of tsunamis around the world, to gain a better understanding the impact of potential tsunamis on coastal communities of the United States. Their work helps inform local, state, and federal coastal planning, protection, and resiliency.

Information focused on geologic aspects of the April 2007 disaster.

Preliminary simulations of the tsunami from the March 11, 2011 M=9.1 subduction zone earthquake offshore of Honshu, Japan.

Preliminary simulation of the tsunami from the September 8, 2017 M=8.1 intermediate-depth earthquake offshore of Chiapas, Mexico

Preliminary simulations of the 2010 Chilean tsunami from the 27 February 2010 M=8.8 subduction zone earthquake, offshore Bio-Bio, Chile

Preliminary simulation of the tsunami from the October 25, 2010 M=7.7 subduction zone earthquake offshore of the Mentawai Islands, Indonesia

USGS and the California Ocean Protection Council (COPC) are supporting development of peer-reviewed map sets for California’s mainland State Waters.

The map sheets display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The total number of sheets varies by area.

On September 29, 2009, an M 8.1 earthquake in the Samoa Islands region of the South Pacific Ocean caused a tsunami that resulted in 100's of lost lives. A rapid-response team of USGS scientists traveled to the Samoa Islands in October-November 2009 to collect time-sensitive data that would have been quickly degraded or destroyed by recovery activity and natural processes.

The tsunami that was triggered by a magnitude 8.1 earthquake on September 29, 2009, caused significant damage and loss of life on Samoa, American Samoa, and Tonga. In the hopes that disasters such as this can be minimized in the future, we attempt to understand the mechanism and impact of this tsunami. The information presented here is focused on geologic aspects of the disaster.

Information about the USGS Pacific Coastal and Marine Science Center's study of tsunami hazards in the Santa Barbara Channel from 1993-2003.

The tsunami that struck New Guinea on July 17, 1998 was the most devastating tsunami since the 1976 Moro Gulf, Philippines, tsunami and may surpass that event (Lockridge and Smith, 1984; Satake and Imamura, 1995). The high reported runups and the tremendous loss of life are of great concern to all, including the international scientific community. Scientists closely examined this event in hopes of...