U.S. Tsunami Programs: A Brief Overview
Peter Folger
Specialist in Energy and Natural Resources Policy
March 15, 2011
Congressional Research Service
7-5700
www.crs.gov
R41686
CRS Report for Congress
P
repared for Members and Committees of Congress
U.S. Tsunami Programs: A Brief Overview
Summary
A 9.0 magnitude earthquake struck off Japan’s northeast coast near Honshu in the afternoon on
Friday, March 11, 2011 (12:46 a.m. eastern time in the United States). The earthquake triggered a
tsunami that has caused widespread devastation to parts of the coastal regions in Japan closest to
the earthquake. The tsunami traveled across the Pacific Ocean, and the National Oceanic and
Atmospheric Administration (NOAA) tsunami warning centers in Hawaii and Alaska issued
tsunami warnings for coastal areas of Hawaii, Guam, the Commonwealth of the Northern
Marianas, American Samoa, Alaska, and California. Although the tsunami caused widespread
damage along the northeast coast of Japan, tsunami warnings issued from the tsunami warning
centers gave the above U.S. Pacific territories, Hawaii, and the U.S. West Coast adequate warning
to prepare for incoming waves.
NOAA’s National Weather Service (NWS) manages the two tsunami warning centers that
monitor, detect, and issue warnings for tsunamis generated in the Pacific Ocean. The NWS
operates the Pacific Tsunami Warning Center (PTWC) at Ewa Beach, HI, and the West
Coast/Alaska Tsunami Warning Center (WC/AKTWC) at Palmer, AK. The National Tsunami
Hazards Mitigation Program (NTHMP) assists states in emergency planning and in developing
maps of potential coastal inundation for a tsunami of a given intensity. The goal of NTHMP is to
ensure adequate advance warning of tsunamis along all the U.S. coastal areas and appropriate
community response to a tsunami event.
The tsunami warning centers monitor and evaluate data from seismic networks and determine if a
tsunami is likely based on the location, magnitude, and depth of an earthquake. If the center
determines that a tsunami is likely, it transmits a warning message to NOAA’s weather
forecasting offices and state emergency management centers, as well as to other recipients. The
centers monitor coastal water-level data, typically with tide-level gages, and data from NOAA’s
network of Deep-ocean Assessment and Reporting of Tsunamis (DART) detection buoys to
confirm that a tsunami has been generated, and if not, to cancel any warnings. Shortly after the
2004 tsunami in the Indian Ocean, Congress passed the Tsunami Warning and Education Act (P.L.
109-424), to enhance and modernize the existing Pacific Tsunami Warning System to increase
coverage, reduce false alarms, and increase the accuracy of forecasts and warnings, among other
purposes. As a result, the array was expanded to a total of 39 DART buoys in March 2008.
Funding for the NOAA tsunami program supports three main categories of activities: (1) warning,
such as the activities of the tsunami warning centers and DART network; (2) mitigation, such as
the activities of NTHMP; and (3) research, including activities conducted by the Pacific Marine
Environmental Laboratory and the National Buoy Data Center. The Government Accountability
Office (GAO) noted that total funding for all these activities ranged from $5 million to $10
million annually between FY1997 and FY2004, but increased after the 2004 Indian Ocean
tsunami from approximately $27 million in FY2005 to $42 million in FY2009. Funding in
FY2010 was $41 million.
Currently, 7 of the 39 DART buoys are not operational. Of the 7 buoys that are not working, 5 are
deployed in the Pacific Ocean. If more DART buoys fail, and regional forecasting capabilities are
impaired, then the NOAA Administrator must notify Congress within 30 days. According to
NOAA, the current continuing resolution (P.L. 112-4) does not allow the NWS to allocate
FY2011 funding to purchase ship time required to repair the 7 DART buoys that are not working.
Congressional Research Service
U.S. Tsunami Programs: A Brief Overview
Contents
Japan Earthquake and Tsunami.................................................................................................... 1
Tsunami Warning Centers ........................................................................................................... 1
The National Tsunami Hazards Mitigation Program .................................................................... 2
Detecting Tsunamis and Issuing Warnings ................................................................................... 2
Warnings Triggered by the March 11, 2011, Tsunami ............................................................ 2
The DART Buoy Network..................................................................................................... 3
Funding for the Tsunami Program ............................................................................................... 4
Additional Reading ..................................................................................................................... 6
Figures
Figure 1. Results from NOAA Model Depicting the March 11, 2011 Tsunami Propagating
Across the Pacific Ocean.......................................................................................................... 3
Figure 2. Locations of DART Buoys ........................................................................................... 4
Contacts
Author Contact Information ........................................................................................................ 6
Congressional Research Service
U.S. Tsunami Programs: A Brief Overview
Japan Earthquake and Tsunami
A 9.0 magnitude massive earthquake struck off Japan’s northeast coast near Honshu in the
afternoon on Friday, March 11, 2011 (12:46 a.m. eastern time in the United States). The
earthquake triggered a tsunami1 that has caused widespread devastation to parts of the coastal
regions in Japan closest to the earthquake. The tsunami traveled across the Pacific Ocean, and the
National Oceanic and Atmospheric Administration (NOAA) tsunami warning centers in Hawaii
and Alaska issued tsunami warnings for coastal areas of Hawaii, Guam, the Commonwealth of
the Northern Marianas, American Samoa, Alaska, and California. The first tsunami waves
reached Hawaii in the early morning of March 11,2 and reached the west coast of the United
States later in the morning (Pacific time). Although the tsunami caused widespread damage along
the northeast coast of Japan, tsunami warnings issued from the tsunami warning centers gave the
above U.S. Pacific territories, Hawaii, and the U.S. West Coast adequate warning to prepare for
incoming waves.3 In addition, the long distance traveled across the Pacific from the earthquake
epicenter attenuated the energy associated with the tsunami thousands of miles from its source. In
contrast, the city of Sendai, Japan, is just 80 miles west of the epicenter.4
Tsunami Warning Centers
NOAA’s National Weather Service (NWS) manages the two tsunami warning centers that
monitor, detect, and issue warnings for tsunamis generated in the Pacific Ocean. The NWS
operates the Pacific Tsunami Warning Center (PTWC) at Ewa Beach, HI, and the West
Coast/Alaska Tsunami Warning Center (WC/AKTWC) at Palmer, AK. The PTWC monitors for
tsunamis and issues warnings for the Hawaiian Islands, the U.S. Pacific territories, and other U.S.
and international interests in the Pacific Basin. The center was established in 1949, after a strong
earthquake and massive landslides off the coast of southwest Alaska caused a disastrous tsunami
for the Hawaiian Islands only hours later. The WC/AKTWC was established in 1967, following a
magnitude 9.2 earthquake that struck Anchorage, AK, in 1964 and caused major earthquake and
localized tsunami damages.5 The WC/AKTWC is responsible for issuing tsunami warnings to
emergency management officials in Alaska, British Columbia (Canada), Washington State,
Oregon, and California. The WC/AKTWC also serves as the center for warning U.S. populations
located in the western Atlantic.
1 A tsunami is a large ocean wave typically caused by a subsea earthquake or volcanic eruption that can cause extreme
destruction when it strikes land.
2 CNN U.S., Tsunami Waves Reach Hawaii, Eye West Coast, CNN Wire Staff, March 11, 2011, http://www.cnn.com/
2011/US/03/11/tsunami/index.html?hpt=T1.
3 Despite the tsunami warnings, some communities along the West Coast and in Hawaii suffered damages. For
example, some boats and harbor facilities were damaged by the tsunami in Crescent City, CA, although most of the
fishing fleet headed out to sea to avoid the waves before they reached the harbor, according to the Los Angeles Times.
Crescent City has suffered tsunami damage in the past, particularly from the 1964 Good Friday earthquake that struck
Alaska. See Maria L. La Ganga, “Crescent City Comes to Grips with Tsunami’s Devastation,” Los Angeles Times,
March 13, 2011, http://www.latimes.com/news/local/la-me-japan-quake-crescent-city-20110313,0,5296998.story.
4 U.S. Geological Survey, Earthquake Hazards Program, http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/
usc0001xgp/#details.
5 See NOAA, NWS, “How TsunamiReady Helps Communities and Counties at Risk,”
http://www.tsunamiready.noaa.gov/.
Congressional Research Service
1
U.S. Tsunami Programs: A Brief Overview
The National Tsunami Hazards Mitigation Program
The National Tsunami Hazards Mitigation Program (NTHMP) assists states in emergency
planning and in developing maps of potential coastal inundation for a tsunami of a given
intensity. The NTHMP also operates tsunami disaster outreach and education programs through
NOAA’s TsunamiReady program. In 1992, NOAA launched the NTHMP to address the credibility
of Pacific tsunami warnings and to reduce the number of “false alarms.” The goal of NTHMP is
to ensure adequate advance warning of tsunamis along all the U.S. coastal areas and appropriate
community response to a tsunami.6
Detecting Tsunamis and Issuing Warnings
The tsunami warning centers monitor and evaluate data from seismic networks and determine if a
tsunami is likely based on the location, magnitude, and depth of an earthquake.7 If the center
determines that a tsunami is likely, they transmit a warning message to NOAA’s weather
forecasting offices and state emergency management centers, as well as to other recipients. The
centers monitor coastal water-level data, typically with tide-level gages, and data from NOAA’s
network of Deep-ocean Assessment and Reporting of Tsunamis (DART) detection buoys to
confirm that a tsunami has been generated, and if not, to cancel any warnings.8
Warnings Triggered by the March 11, 2011, Tsunami
Initial warnings of an impending tsunami were first issued by the PTWC based on seismic
information before the network of DART buoys and tide gages actually detected a wave
generated by the earthquake.9 According to NOAA, initial tsunami warnings are normally based
only on seismic information to provide the earliest possible alert.10 Because tsunamis travel more
slowly than seismic waves, confirmation of a tsunami may take much longer than confirmation of
an earthquake. That was the case for the March 11, 2011, tsunami. The DART network first
detected the earthquake-triggered wave 27 minutes after the earthquake struck at 2:46 p.m. local
time in Japan,11 confirming that a tsunami had been generated and could lead to significant
widespread inundation around the Pacific Ocean. Figure 1 shows results from a model depicting
the tsunami wave propagation across the Pacific Ocean.
6 NOAA FY2012 Blue Book, Chapter 5, National Weather Service, p. 691, http://www.corporateservices.noaa.gov/
nbo/fy12_presidents_budget/National_Weather_Service_FY12.pdf.
7 Nearly all tsunamis are triggered by subsea earthquakes, although some may also be caused by underwater volcanic
eruptions or landslides.
8 U.S. Government Accountability Office, U.S. Tsunami Preparedness: NOAA Has Expanded Its Tsunami Programs,
but Improved Planning Could Enhance Effectiveness, GAO-10-490, April 2010, p. 5.
9 DART buoy 21418; telephone conversation with Laura Furgione, Deputy Director, National Weather Service, March
15, 2011.
10 NWS, Pacific Tsunami Warning Center, About PTWC Messages, http://ptwc.weather.gov/ptwc/about_messages.php.
11 Telephone conversation with Laura Furgione, March 15, 2011.
Congressional Research Service
2
U.S. Tsunami Programs: A Brief Overview
Figure 1. Results from NOAA Model Depicting the March 11, 2011 Tsunami
Propagating Across the Pacific Ocean
Source: NOAA Center for Tsunami Research, Pacific Marine Environmental Laboratory,
http://nctr.pmel.noaa.gov/honshu20110311/.
Notes: Colors indicate the wave amplitude in centimeters (see scale bar on right side of figure); contour labels
indicate the computed tsunami arrival times. Black triangles indicate location of Deep-ocean Assessment and
Reporting of Tsunamis (DART) detection buoys.
The DART Buoy Network
NOAA first completed a six-buoy DART array in 2001 in the Pacific Ocean. Shortly after the
2004 Indian Ocean earthquake and tsunami that killed over 200,000 people, Congress passed
H.R. 1674, the Tsunami Warning and Education Act (P.L. 109-424), to enhance and modernize
the existing Pacific Tsunami Warning System to increase coverage, reduce false alarms, and
increase the accuracy of forecasts and warnings, among other purposes. In part, the 2004 tsunami
provided the impetus to expand and upgrade the DART system and to improve the U.S. capability
to detect and issue warnings for tsunamis generally. As a result, the array was expanded to a total
of 39 DART buoys in March 2008.12 (See Figure 2.)
12 According to NOAA, 33 of the DART buoys are deployed in the Pacific Ocean, and the rest are deployed in the
Atlantic Ocean and Caribbean. NOAA National Data Buoy Center, Deep-ocean Assessment and Reporting of
Tsunamis (DART) Description, http://www.ndbc.noaa.gov/dart/dart.shtml.
Congressional Research Service
3
U.S. Tsunami Programs: A Brief Overview
Figure 2. Locations of DART Buoys
Source: NOAA National Data Buoy Center, http://www.ndbc.noaa.gov/dart.shtml
Notes: The United States owns and operates 39 of the DART Buoys.
Currently, 7 of the 39 buoys are not operational and in need of repair. Of the 7 buoys that are not
working, 5 are deployed in the Pacific Ocean. Other countries also operate DART buoys in the
Pacific (e.g., Australia and Russia), but if another U.S. DART buoy ceases to function less than
80% of the U.S. DART network would be operational. The Tsunami Warning and Education Act
(P.L. 109-424) requires that NWS ensure that maintaining operations of tsunami detection
equipment is the highest priority within the tsunami forecasting and warning program at NOAA.
Further, P.L. 109-424 requires that the NOAA Administrator notify Congress13 within 30 days of
(1) impaired regional forecasting capabilities due to equipment or system failures; and (2)
significant contractor failures or delays in completing work associated with the tsunami
forecasting and warning system.14
Funding for the Tsunami Program
Funding for the NOAA tsunami program supports three main categories of activities: (1) warning,
such as the activities of the tsunami warning centers and DART network; (2) mitigation, such as
13 Specifically, P.L. 109-424 requires the NOAA Administrator to notify the Committee on Commerce, Science, and
Transportation in the Senate and the Committee on Science (now Science, Space, and Technology) in the House.
14 The statute does not define what is considered impairment of the forecasting abilities, or what is a threshold for
significant contractor failures or delays. However, the committee report accompanying the bill states that NWS is
required to notify Congress when the tsunami forecasting capabilities are impaired for more than three months; U.S.
Congress, House Science, United States Tsunami Warning and Education Act, report to accompany H.R. 1674, 109th
Cong., 2nd sess., 2006, H.Rept. 109-698, p. 10. NWS uses an 80% operational threshold as its internal guideline;
Telephone conversation with Laura Furgione, March 15, 2011.
Congressional Research Service
4
U.S. Tsunami Programs: A Brief Overview
the activities of NTHMP; and (3) research, including activities conducted by the Pacific Marine
Environmental Laboratory and the National Buoy Data Center.15 In the NOAA budget, these
activities are cross-cutting among different activities under the NWS line item.16 GAO, which
analyzed funding data for the three general categories, noted that total funding for all these
activities ranged from $5 million to $10 million annually between FY1997 and FY2004, but
increased after the 2004 Indian Ocean tsunami from approximately $27 million in FY2005 to $42
million in FY2009. According to GAO, the proportion of funding allocated to warning activities
increased from about 40% of the total in FY2004 to approximately 70% of the funding in
FY2009.17 The proportion allocated to mitigation decreased from approximately 50% of the total
in FY2004 to about 30% in FY2009, while the proportion for research remained steady between
about 6% to 10%.
Funding for the NWS tsunami program for FY2010 was approximately $41 million, allocated as
follows:
• $23 million—Strengthen U.S. Tsunami Warning Program;
• $13 million—Spectrum Auction funding;18
• $4 million—NWS/Local Warnings and Forecasts; and
• $1 million—Office of Oceanic and Atmospheric Research/Pacific Marine
Environmental Laboratory.19
In 2010, the Government Accountability Office (GAO) found that NOAA had made progress
since 2005 in expanding and strengthening its tsunami warning and mitigation capabilities,
including the deployment of the 39 DART buoys. GAO also found that operating and maintaining
the buoys has proved difficult and costly, consuming about 28% of the total NOAA Tsunami
Warning Program budget in FY2009.20 GAO noted that NOAA is exploring ways to reduce
maintenance costs by improving buoy reliability.
According to NOAA, the current continuing resolution (P.L. 112-4) does not allow the NWS to
allocate FY2011 funding to purchase ship time required to repair the seven DART buoys that are
not working.21 As noted above, the delay or failure in completing work associated with the
15 U.S. Government Accountability Office, U.S. Tsunami Preparedness: NOAA Has Expanded Its Tsunami Programs,
but Improved Planning Could Enhance Effectiveness, GAO-10-490, p. 7.
16 For example, the FY2010 enacted budget contains a line item: Strengthen U.S. Tsunami Warning Network—$23.264
million. However, research activities for tsunamis are included in the overall budget for the Pacific Marine
Environmental Laboratory and for the National Buoy Data Center.
17 U.S. Government Accountability Office, U.S. Tsunami Preparedness: NOAA Has Expanded Its Tsunami Programs,
but Improved Planning Could Enhance Effectiveness, GAO-10-490, p. 8.
18 Starting in FY2009, the tsunami program received funding from the proceeds of the Federal Communication
Commission’s auctioning of broadcast frequency spectrum. In FY2012, the program will be augmented by $12.7
million from auction proceeds, according to NOAA. Total funding received from auction proceeds will be
approximately $50 million for the tsunami program at the end of FY2012, according to GAO.
19 E-mail from Lara Hinderstein, NOAA Budget Outreach and Communications, March 11, 2011.
20 U.S. Government Accountability Office, U.S. Tsunami Preparedness: NOAA Has Expanded Its Tsunami Programs,
but Improved Planning Could Enhance Effectiveness, GAO-10-490, p. 21.
21 Approximately $4 million would required, according to NOAA. Telephone conversation with Laura Furgione, March
15, 2011.
Congressional Research Service
5
U.S. Tsunami Programs: A Brief Overview
tsunami forecasting and warning system by contractors should also trigger notification of
Congress by the NOAA Administrator under P.L. 109-424.
Additional Reading
CRS Report RL33861, Earthquakes: Risk, Detection, Warning, and Research, by Peter Folger
CRS Report RL33436, Japan-U.S. Relations: Issues for Congress, coordinated by Emma
Chanlett-Avery
CRS Report R41023, Haiti Earthquake: Crisis and Response, by Rhoda Margesson and Maureen
Taft-Morales
Author Contact Information
Peter Folger
Specialist in Energy and Natural Resources Policy
pfolger@crs.loc.gov, 7-1517
Congressional Research Service
6