U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2006–3012

April 2006

Improving Earthquake and Tsunami Warnings for the 

Caribbean Sea, the Gulf of Mexico, and the Atlantic Coast

T

he magnitude-9 Sumatra–Andaman Islands 

earthquake of December 26, 2004, increased 

awareness in the United States of the destructive hazard posed by earthquakes and tsunamis. The 

U.S. Government, working with international partners, 

is responding with a real-time system that will significantly improve global earthquake and tsunami monitoring. This fact sheet describes a project to improve 

earthquake and tsunami monitoring along a major portion of our vulnerable coastal regions, the Caribbean 

Sea, the Gulf of Mexico, and the Atlantic Ocean. The 

project is a result of collaboration between the U.S. 

Geological Survey (USGS) and the National Oceanic 

and Atmospheric Administration (NOAA).

Earthquake and Tsunami Hazard Assessment and 

Research

Seismically active areas of the Caribbean Sea region 

pose a tsunami risk for Caribbean islands, coastal areas 

along the Gulf of Mexico, and the Atlantic seaboard of 

North America. Nearly 100 tsunamis have been reported 

for the Caribbean region in the past 500 years, including 

14 tsunamis reported in Puerto Rico and the U.S. Virgin 

Islands. In this time, 30 tsunamis caused significant damage and as many as 9,600 recorded fatalities. During the 

past 150 years, nearly 2,000 deaths were attributed to tsunamis. Over the same period, the loss of life in the Caribbean was five times higher than along the combined coasts 

of Hawaii, Alaska, California, Oregon, and Washington. In 

1946, a magnitude 8.0 earthquake just north of Hispaniola 

generated a tsunami that killed a reported 1,600 people in 

the region. 

With several hundred million people now living in 

coastal areas surrounding the Caribbean, and with major 

earthquakes occurring on average every 50 years, it is not 

a question of whether a destructive tsunami will occur but 

when. A need therefore exists for a Caribbean tsunami 

early-warning system that serves the entire region. An 

additional need exists for 

increased public education 

and outreach on the hazards 

posed by tsunamis and how 

to respond to warnings. 

Such education is especially 

important in the Caribbean 

where tsunamis have devastated coasts within minutes 

of a local earthquake.

Monitoring System for 

Warning Guidance and 

Mitigation

As part of the President’s 

initiative for an improved 

tsunami warning and detection system, NOAA and 

the USGS are expanding 

earthquake and tsunami 

seismometer

power and 

communications

system

A typical USGS earthquake monitoring station consists of a broadband seismometer, a 

multichannel digitizer, and telecommunications 

equipment to transmit ground-shaking data 

instantaneously to the 24/7 National Earthquake 

Information Center in Golden, Colo. 
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Plate boundariesVolcanoes

Earthquake epicenters 1610–2004, M > 6

0–69 km 70–299Tsunami-generating earthquakes

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Improved earthquake and tsunami monitoring in the Caribbean. The map shows the seismicity and tectonic setting of the region as well as planned ing stations. The planned seismic stations will be affiliated with the Global Seismographic Network (GSN), which is funded jointly by the National ScUSGS. NOAA’s National Data Buoy Center operates DART (Deep-ocean Assessment and Reporting of Tsunamis) stations.
monitoring in the Caribbean and Atlantic coastal regions. 

This effort will be conducted in partnership with eight 

Caribbean host nations and will directly address the needs 

spelled out by the Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and 

Tsunami Relief, 2005 (http://www.whitehouse.gov/news/

releases/2005/05/20050511-5.html). Funds will be targeted at improved earthquake detection and notification 

capability, deployment of a system for real-time detection of tsunami waves, faster tsunami warning capability, focused studies to address tsunami inundation and 

earthquake hazard modeling, and improved education and 

training.

The Role of NOAA: Tsunami Detection and Warning

As part of the President’s initiative to improve domestic tsunami warnings, NOAA will deploy 39 Deep-ocean 

Assessment and Reporting of Tsunamis (DART II) buoy 

stations in the Pacific (32), Atlantic (5), and Caribbean 

(2) regions to detect and verify tsunami waves. Together, 

the earthquake- and tsunami-monitoring instrumentation 

will provide the United States with nearly 100 percent 

detection capability for a U.S. coastal tsunami. Notification of 

tsunami-generating earthquakes will originate from USGS 

National Earthquake Information Center (NEIC) in a 

matter of minutes after rupture initiation, allowing the 

NOAA tsunami warning center to analyze the quake for 

tsunamigenic potential and alert vulnerable coastal areas 

well ahead of tsunami waves. The integrated system is 

expected to be in place by mid-2007.

The Role of the USGS: Earthquake Detection 

and Warning

Warning of a potentially dangerous tsunami begins 

with rapid earthquake detection and notification. To 

improve these capabilities in the Caribbean region, the 

USGS will work with host countries to install or upgrade 

12 seismic monitoring sites distributed around the various 

earthquake source zones. The new stations will be affiliated with the Global Seismographic Network (GSN), a 

collaborative effort of the USGS, the National Science 

Foundation (NSF), and the Incorporated Research Institutions for Seismology (IRIS). Long-term operation will be 

conducted by USGS in cooperation with partners from the 

NOAA developed Deep-ocean 

Assessment and Reporting of 

Tsunamis (DART II) buoy stations for 

early detection, measurement, and 

real-time reporting of tsunamis in the 

open ocean. Two Caribbean and five 

Atlantic DART II buoy stations will be 

deployed in regions with a history of 

tsunami generation.

Optional Sensors

wind

barometric pres.

Seasurface temp.

 & conductivity

Air temp.

Humidity
host countries. Equipment at each station will conform to 

standards in place for the National U.S. “backbone” array 

and will consist of the following:

• ground-motion sensors to detect distant tsunamigenerating earthquakes and to measure the effects 

of strong shaking from local earthquakes,

• high-resolution, digital data-acquisition system, 

• real-time satellite telemetry system that will 

transmit ground-motion data to automated 

processing systems at the USGS National 

Earthquake Information Center (NEIC) and the 

NOAA tsunami warning centers, and

• robust and redundant power systems to maximize 

uptime in the event of local disasters due to 

earthquakes, tsunamis, and hurricanes. 

 The planned seismic stations in the Caribbean will 

allow more accurate, timely, and responsive monitoring in 

the region by lowering the earthquake-magnitude detection threshold, reducing hypocenter error, and decreasing 

NEIC earthquake notification time.

Part of a Larger Picture of Hazard Mitigation Within 

the USGS

The tsunami hazards for coastlines of the Gulf of 

Mexico, Atlantic Ocean, and Caribbean islands are unique 

in that practically all the known causes of tsunamis are 

present, including earthquakes, submarine landslides, and 

island volcanoes. For example, large submarine landslides 

pose significant tsunami hazards along with earthquakes. 

Researchers think that past landslides resulted from 

ongoing plate-tectonic movement that tilted the seafloor 4° down to the north. The tilt caused massive slope 

failures that appear to be continuing, as evidenced by 

large fissures in the seafloor. The new monitoring system 

will focus on earthquakes and tsunamis and complement 

existing USGS and NOAA scientific investigations in the 

region, including earthquake hazard assessment, tectonics 

and active fault studies, tsunami hazard and inundation 

modeling, and submarine landslide hazard studies.

International Cooperation Required

Close international cooperation among all the Caribbean, South American, and Latin American nations 

threatened by earthquakes and tsunamis will be essential 

to assure success. The primary organization for seismic 

monitoring in the Caribbean region is the Middle America 

Seismograph Consortium (MIDAS). The USGS has a 

long-term partnership with MIDAS and its members and 

will continue to work through this organization to coordinate efforts in the region. Members of MIDAS include 

the U.S. territory Puerto Rico, Turks and Caicos Islands, 

Dominican Republic, Jamaica, Tobago, Trinidad, Barbados, Antigua/Barbuda, Honduras, and Panama. 

For information contact:

Earthquake Hazards Program

U.S. Geological Survey

Golden, CO 80401

http://earthquake.usgs.gov/

http://www.usgs.gov/

National Oceanic and Atmospheric Administration

NOAA Tsunami Program Office

Silver Spring, MD 20910

http://www.tsunami.gov/

http://www.noaa.gov/

This fact sheet is available online at 

http://pubs.usgs.gov/fs/2006/3012

Written by Dan McNamara, Jill McCarthy, and Harley Benz

Publication layout by Margo Johnson

vertical exaggeration = 8 km

A NOAA image of the ocean-floor bathymetry north of Puerto Rico. Two 

ancient submarine landslides are visible as head scarps (labeled Loiza 

and Arecibo Amphitheaters). Seafloor fissures are indicated by black 

arrows, and dashed lines outline debris flows from past failures (map 

by Uri Ten Brink of the USGS).

The National Oceanic and Atmospheric Administration 

(NOAA), an agency of the U.S. Commerce Department, 

is dedicated to enhancing economic security and national 

safety through the prediction of and research on weatherand climate-related events and providing environmental 

stewardship of our Nation’s coastal and marine resources. 

Through the emerging Global Earth Observation System 

of Systems (GEOSS), NOAA is working with its Federal partners and nearly 60 countries to develop a global 

monitoring network that is as integrated as the planet it 

observes.