Coast Guard Cutter Oak crew assists with scientific research mission

Courtesy Photo | A map of the ocean floor north of Puerto Rico, used by the U.S. Geological Survey and the Woods Hole Oceanographic Institution, displays the areas of focus for scientific research. The purpose of the research is to record seismic data for approximately one year to supplement data from land-based seismographs operated by the Global Seismograph Network, the Puerto Rico Seismic Network, and others. (Map courtesy of the U.S. Geological Survey and the Woods Hole Oceanographic Institution)  

SAN JUAN, PUERTO RICO

06.17.2015

Story by Petty Officer 2nd Class Anthony Soto 

U.S. Coast Guard District 7 PADET Jacksonville   

SAN JUAN, Puerto Rico - The crew aboard the Coast Guard Cutter Oak, along with scientists and engineers from the U.S. Geological Survey and the Woods Hole Oceanographic Institution, completed a mission May 20-23, where they deployed six ocean-bottom seismograph instruments on the seafloor in an area of the Caribbean Sea known as the Puerto Rico Trench.

The OBS instruments will be recording data for approximately one year to supplement data from land-based seismographs operated by the Global Seismograph Network, the Puerto Rico Seismic Network, and others. The instruments were designed and built by WHOI, and were deployed in an area approximately 100 miles north of Puerto Rico in water depths up to 3.5 miles.

“The OBS instruments are key to improving are our ability to image the fault systems along the major plate boundary,” said Dr. Nathan Miller, USGS chief scientist on the research cruise. “The temporary instruments expand the seismic network near Puerto Rico significantly and allow us to record seismic waves along paths we cannot sample using land instruments. This improves our ability to image the subduction zone structure at depth and will enable seismologists to record and locate earthquakes associated with tectonic plate motion around the Puerto Rico Trench.”

The work is part of a project led by USGS scientist Uri ten Brink, to better assess the seismic and tsunami hazards in the tectonically active Caribbean region.

“Large tsunamis associated with earthquake activity have affected this area historically with fatalities in Puerto Rico and Hispaniola as recently as 1946. Many geologic structures observed in submarine areas may pose additional hazards,” said ten Brink. “Because four million U.S. citizens live along the coastlines of Puerto Rico and the Virgin Islands, the risk to life and economic infrastructure is high. This work is fundamental to determining the likely hazards and their causative mechanisms and will help the USGS provide the scientific information needed to improve building codes, zoning, and educating the public on how best to respond to these kinds of hazards.”

“Seafloor instruments are a critical part of our research. We are truly thankful to the captain and crew of the Coast Guard Cutter Oak for assisting us with this deployment,” said Miller.

The Cutter Oak was selected for this mission primarily due to its open deck space and its crane, which can lift the 1,200-pound OBS's.

"We are excited to be a part of the deployment of these sensors, that hopefully will lead to greater knowledge about our shifting tectonic plates and will ultimately translate to improved hazard preparedness and more resilient coastal communities," said Lt. Cmdr. Whitney Houck, commanding officer of the Cutter Oak. "The sensor deployment went very well, and both teams integrated seamlessly."

For more information on the USGS research for this project, contact Dr. Nathan Miller at [e-mail].

For more information on the Cutter Oak’s role in this mission, contact the unit’s public affairs officer, Lt. j.g Mateusz Lemanski at [e-mail]. Pictures are available upon request.

• Date Taken: 06.17.2015
• Date Posted: 06.17.2015 17:18
• Story ID: 167022
• Location: SAN JUAN, PR