USGS - science for a changing world

Pacific Coastal and Marine Science Center

Drawing of The Great Wave; link to our Tsunamis and Earthquakes web page.


Notes From the Field...

Field Study of the Effects of the 29 September 2009 Samoa Tsunami

About the field study:
September 30, 2009

Illustration map of the globe showing location of Samoa Islands.

On September 29, 2009, a magnitude-8.0 submarine earthquake occurred at 6:48a.m. Samoa Standard Time approximately 190 km (120 mi) south of Samoa and triggered a tsunami that caused 191 deaths and widespread damage in Samoa, American Samoa, and Tonga. Eyewitnesses reported three to seven tsunami waves; the largest were higher than 5 m and reached more than 500 m inland.

A rapid-response team of USGS scientists went to the region to collect data before it was degraded or destroyed by recovery activity and natural processes. USGS oceanographer Bruce Jaffe arrived in Pago Pago, on the island of Tutuila, American Samoa, on October 4 and was joined later in the week by Bruce Richmond, Mark Buckley, Guy Gelfenbaum, Steve Watt, and Alex Apotsos. Oceanographer Walter Dudley of the University of Hawai‘i, Hilo, worked with the USGS team. The team collected time-sensitive data on both American Samoa and Samoa to document the variation in the height of tsunami waves and distance the waves traveled inland. They also studied the transport of sediment and other debris; documented erosion caused by the tsunami waves, and made other observations critical to the better understanding of tsunami impacts and processes. The information this team collected will be used to lessen death and destruction for future tsunamis.

Read the reports sent from the region in by the USGS scientists, with post-survey follow-ups.

Map of Samoa Islands.
Map of the Samoa Islands, circa 2002, courtesy of National Park Service

DISCLAIMER: This material is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.


Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: PCMSC Web Team
Page Last Modified: 13 January 2010 (lzt)