*Fact Sheet: Draft 3.2*

Improving Earthquake and Tsunami Warning for the Caribbean Sea,

Gulf of Mexico, and the Atlantic Coast

*Summary*

> *The great Sumatra Earthquake of December 26, 2004, increased the
> awareness in the United States to the destructive hazard posed by
> earthquakes and tsunamis. The United States government, working with
> international partners, is responding with a real-time system that
> will significantly improve global earthquake and tsunami monitoring.
> This report focuses on a collaborative USGS NOAA project to improve
> monitoring along a major portion of our vulnerable coastal regions,
> the Caribbean Sea, the Gulf of Mexico and the Atlantic Ocean.*

######## *Earthquake and Tsunami Hazard Assessment and Research*

Seismically active areas of the Caribbean pose a tsunami risk for the
Caribbean Sea, the Gulf of Mexico, and the Atlantic coast 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, including reports of as many as 9600 fatalities. During the last
150 years, nearly 2000 deaths are attributed to tsunamis. This
represents a loss nearly 5 times greater than in Hawaii, Alaska and the
U.S. West coast combined for that time period. Most recently, a
magnitude 8.1 earthquake in 1946 just north of the Island of Hispaniola
generated a tsunami that killed a reported 1,600 people and was detected
as far as Atlantic City, New Jersey.

With several hundred million people now living in coastal areas
surrounding the Caribbean, and with major earthquakes occurring on
average every 50 years, scientists say it is not a question of if a
destructive tsunami will occur but when. There is thus a need for a
Caribbean tsunami early warning system that services the entire region.
There is also a need for increased public education and outreach on the
hazards posed by tsunamis and how to respond to warnings when issued.
This need is especially great in the Caribbean where tsunamis have
devastated coasts within minutes of a local earthquake.

## 

## **Monitoring System for Warning Guidance and Mitigation**

## In response to this need, the U.S. Government has funded the U.S. Geological Survey (USGS) and the National Oceanographic and Atmospheric Administration (NOAA) to expand earthquake and tsunami monitoring in the Caribbean and Atlantic coastal region. This effort, which will be conducted in partnership with eight host nations in the Caribbean, directly addresses the needs spelled out by the Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Tsunami Relief, 2005. Funds will be targeted at improved earthquake detection and notification capability, deployment of a real-time tsunami wave detection system, faster tsunami warning capability, focused studies to address tsunami inundation and earthquake hazard modeling, and improved education and training.

# **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 insure success. The primary organization for seismic
monitoring in the Caribbean region is the Mid America Seismology
Consortium (MIDAS). The USGS has a long-term partnership with MIDAS and
its member countries, and will continue to work through this
organization to coordinate efforts in the region. Partner nations of
MIDAS include: the US territory Puerto Rico, Turks and Caicos Islands,
The Dominican Republic, Jamaica, Trinidad, Barbados, Antigua, Honduras
and Panama.

######### The Role of the USGS: Earthquake Detection and Warning

Warning of a potentially dangerous tsunami begins with rapid earthquake
detection and notification. To improve earthquake detection and
notification processes in the Caribbean region, USGS will work with host
countries to install or upgrade twelve seismic monitoring sites
distributed around the various earthquake source zones. The new stations
will be affiliated with the Global Seismic Network (GSN), and long-term
operation will be the responsibility of the USGS and the National
Science Foundation (NSF) in cooperation with partners from the host
countries. Equipment at each station will conform to standards in place
for the National U.S. "backbone" array and will consist of:

## Ground motion sensors to detect distant tsunamigenic earthquakes and 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,

## Robust and redundant power system 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. 

## 

## **The Role of NOAA: Tsunami Detection and Warning**

## NOAA, in turn, will deploy an array of 39 next generation Deep-ocean Assessment and Reporting of Tsunami (DART II) stations in the Pacific (32), Atlantic (2) and Caribbean regions (5) to detect and verify tsunami waves. Together, the seismic and tsunami monitoring instrumentation will provide the United States with nearly 100% detection capability for a U.S. coastal tsunami. Notification of tsunamigenic earthquakes will be generated by the USGS NEIC in a matter of minutes after the rupture initiation, allowing the NOAA tsunami warning center to warn vulnerable coastal areas, well ahead of the most destructive tsunami waves. The integrated system is expected to be in place by mid-2007.

![](media/image1.jpeg){width="3.188888888888889in"
height="2.392361111111111in"}![](media/image2.jpeg){width="3.0131944444444443in"
height="2.2597222222222224in"}A typical USGS earthquake monitoring
station consists of a broadband seismometer (photographed to the right),
a multi-channel digitizer and telecommunications equipment to transmit
ground shaking data instantaneously to the 24/7 National Earthquake
Information Center in Golden, CO. Construction of the communications
equipment is pictured above.

> ![](media/image3.jpeg){width="5.9944444444444445in"
> height="4.631944444444445in"}
>
> Proposed USGS and NOAA Caribbean earthquake and tsunami monitoring
> system.

# **Part of a Larger Picture of Hazard Mitigation Within the USGS**

The tsunami hazards for coastlines in the Gulf of Mexico, Atlantic Ocean
and Caribbean Islands are unique in that practically all the known
causes of tsunamis are present. For example, large submarine landslides
pose significant Tsunami hazard along with earthquakes. Researchers
believe these landslides resulted from continued plate tectonic movement
that tilted the seafloor 4° to the north. The tilt caused massive slope
failures, which appears to continue, 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:

1)  earthquake hazard assessment,

2)  tectonics and active fault studies,

3)  tsunami hazard and inundation modeling,

4)  submarine landslide hazard studies.

![](media/image4.png){width="3.720138888888889in"
height="3.759027777777778in"}

To the left is an image of the ocean floor bathymetry north of Puerto
Rico.. Two past submarine landslides (labeled Loiza and Arecibo
Amphitheaters) are evident. Sea floor fissures are pointed to by black
arrows. Dashed lines Outline debris flow from past failures. (map by Uri
Ten Brink of the USGS)

For information contact:

Earthquake Hazards Program

U.S. Geological Survey

Golden, CO 80401

<http://earthquake.usgs.gov/>

http://www.usgs.gov

Written by: Dan McNamara, Jill McCarthy, Harley Benz