US NWS Pacific Tsunami Warning Center (PTWC)
Meteotsunami Animation: U.S. East Coast, June 2013
- Title
- Meteotsunami Animation: U.S. East Coast, June 2013
- Runtime
- 1:37
- Date posted
- 13 years ago
- Description
- PTWC scientists used their tsunami forecast model, RIFT, to simulate how a weather-generated tsunami, or meteotsunami, may have propagated off of the east coast of the United States in the north Atlantic Ocean on June 13, 2013. A "derecho," or a rapidly-moving coherent storm front, traveled eastward across the US's mid-Atlantic states and out over the ocean as an atmospheric pressure anomaly. It appears in the animation as a prominent "negative" wave or trough in the sea's surface. It generates meteotsunami waves as it moves, and when it reaches the edge of the continental shelf (seen as a change from light blue to darker blue colors in the ocean) the waves jump or "spike" in amplitude there and propagate along the shelf's edge. The meteotsunami waves reflect landward from the shelf's edge due to the rapid change in wave velocity there (tsunami waves travel much faster in deeper water), then reflect again seaward from the coastline. Thus these waves become trapped in the shallow wa...
- Title
- Tsunami Animation: Haida Gwaii, Canada October 27, 2012
- Runtime
- 1:37
- Date posted
- 13 years ago
- Description
- This animation shows how PTWC's real-time tsunami forecast model, RIFT, predicts the behavior of the tsunami following the 7.8 magnitude earthquake in the Haida Gwaii Islands, Canada on October 27, 2012. The animation covers a 12-hour period followed by an "energy map" showing the forecasted maximum heights of open-ocean tsunami waves over a 24-hour period. The animation concludes with RIFT's estimates for tsunami wave heights on impacted coastlines in the northeast Pacific Ocean and in the Hawaiian Islands. Note that these coastal values are higher than the values immediately offshore. Note also that the highest values are near the earthquake in Canada and on tsunami-facing coastlines in Hawaiʻi. This tsunami was not large enough for damaging waves to wrap around the islands and it spared the island of Oʻahu, Hawaii's major population center, but it did cause some minor damage on the island of Molokaʻi.
This model also shows the tsunami waves reflecting off of the Hawa...
- Title
- Tsunami Animation: Hawaii 1975
- Runtime
- 1:18
- Date posted
- 13 years ago
- Description
- NEW VERSION AT https://youtu.be/0Ho0BzF2eCY
Not all tsunamis in the Hawaiian Islands come from overseas. On the early morning of November 29, 1975, a 7.7 magnitude* earthquake struck the southeast coast of the Big Island of Hawaii and generated a tsunami as high as 48 ft. (14.6 m). A 26 ft. (7.9 m) high wave killed two campers at the Halape Campground in Hawaii Volcanoes National Park. The tsunami also damaged property elsewhere on the Island of Hawaii and smaller non-destructive waves traveled as far as Alaska, California, Japan, and Samoa. For more information about this earthquake please see http://hvo.wr.usgs.gov/earthquakes/destruct/1975Nov29/
Our animation shows how this tsunami may have propagated in the Hawaiian Islands, transitioning at its end to an "energy map" showing the maximum wave heights over the 6-hour period that the animation covers. Note how the waves wrap around the islands and reach Honolulu in about 45 minutes. The campers in Ha...
- Title
- Nine Years of Earthquakes in Southeast Asia
- Runtime
- 2:06
- Date posted
- 13 years ago
- Description
- Following the devastating 26 December 2004 Indian Ocean tsunami PTWC expanded its services into that region while the nations there built their own tsunami warning system. India, Indonesia, and Australia now provide tsunami information for the Indian Ocean, and PTWC discontinued its Indian Ocean services on 31 March 2013. Before that date PTWC had to respond to dozens of tsunami-causing earthquakes in southeast Asia, one of the most seismically active areas on earth. This animation shows the earthquake activity in this region from 2004 through 2012 and includes some notable tsunami-causing earthquakes (moment magnitude, location, and date):
9.1 Sumatra-Andaman Is., 26 December 2004
8.6 Nias, Indonesia, 28 March 2005
7.7 Java, Indonesia, 17 July 2006
8.1 Solomon Islands, 1 April 2007
8.5 Padang, Indonesia, 12 September 2007
7.9 Padang, Indonesia, 12 September 2007
7.7 Papu...
- Title
- The Great Tōhoku-Oki Earthquake: Its Foreshock, Mainshock, and Aftershocks
- Runtime
- 1:17
- Date posted
- 13 years ago
- Description
- This animation shows the 9.0 magnitude earthquake that struck off the coast of Japan's Tōhoku-Oki region on 11 March 2011 and the first six months of its aftershocks.
For animations of the resulting tsunami, please see:
"flat earth" (Mercator) - http://youtu.be/EG507Y40d4U
"rotating globe" - http://youtu.be/feBtPsJH25c
This sequence will allow you to compare the more typical background level of seismic activity in Japan with the elevated levels of activity resulting from the great earthquake and its aftershocks. You will also be able to see the size and shape of the "rupture zone"--the portion of the fault that moved during the great earthquake--as revealed by the cluster of aftershocks. Also look for the 7.2 magnitude foreshock that preceded the 9.0 magnitude mainshock two days earlier on March 9.
- Title
- The 27 February 2010 Maule, Chile Earthquake and its Aftershocks
- Runtime
- 0:57
- Date posted
- 13 years ago
- Description
- This animation shows the 8.8 magnitude earthquake that struck Maule, Chile on 27 February 2010 and the first six months of its aftershocks.
These almost nine-months' worth of earthquake data will allow you to compare the more typical background level of seismic activity in Chile with the elevated levels of activity resulting from the great earthquake and its aftershocks. You will also be able to see the size and shape of the "rupture zone"--the portion of the fault that moved during the great earthquake--as revealed by the cluster of aftershocks.
For animations of the the tsunami, please see:
Mercator: http://youtu.be/RO16edaxoV0
Rotating globe: http://youtu.be/L2mz-dETib8
- Title
- Thrust vs. Strike-Slip Mechanisms in PTWC's Tsunami Forecast Model
- Runtime
- 1:21
- Date posted
- 13 years ago
- Description
- On April 11, 2012, PTWC scientists responded to a pair of very unusual earthquakes, 8.6 and 8.2 magnitude strike-slip events, the largest of this type ever recorded. They did not know the quakes were strike-slip at first, and due to their large size they assumed the worst-case scenario: thrust-type earthquakes that could generate dangerous tsunamis. Therefore they put the Indian Ocean in a Tsunami Watch status. But in less than an hour they figured out the strike-slip nature of the quakes and that they were less likely to generate tsunamis, and when their instruments confirmed that the quakes did not generate tsunamis they canceled the Tsunami Watch.
PTWC scientists and their colleagues later wrote a paper about this event, "Real-time Forecasting of the April 11, 2012 Sumatra Tsunami," published in Geophysical Research Letters:
http://www.agu.org/pubs/crossref/pip/2012GL053081.shtml
As they describe in their paper, this related animation s...
- Title
- TSUNAMI WARNING!
- Runtime
- 6:03
- Date posted
- 13 years ago
- Description
- Since an earthquake's fastest wave, its primary or P-wave, travels about 50 times faster than the fastest tsunami waves, a tsunami warning center will issue its initial tsunami warning based on seismic data alone. This animation uses the 9.1 magnitude Great Tohoku-Oki Earthquake and its tsunami to illustrate how the Pacific Tsunami Warning Center (PTWC) issued its first warning message less than 9 minutes after the earthquake and 19 minutes before the tsunami reached the first sea-level sensor not damaged by the earthquake, a deep-ocean or DART instrument. After the P-wave sequence the animation will then speed up to show the tsunami spreading through the world's oceans over a 48 hour period and highlight tsunami measurements by coastal and DART sensors.
- Title
- How to Make a Tsunami
- Runtime
- 1:06
- Date posted
- 13 years ago
- Description
- This cartoon shows schematically how a subduction earthquake generates a tsunami. The green material is the lithosphere (which is brittle) and the purple-red material is the asthenosphere (which, while still solid, is deformable). The lithosphere is divided into the overriding (continental) plate on the right and the downgoing (oceanic) plate on the left. The overriding plate is locked against the downgoing plate, so as the downgoing plate subducts, the overriding plate is progressively deformed. The front edge of the overriding plate is flexed downwards while the coastline is lifted. After a few hundred years, so much strain energy has been stored in the system (think of a spring that is wound up too tight) that something has to give. The result is an earthquake. The earthquake relieves the accumulated strain in just a matter of minutes, during which the overriding plate relaxes back to its original unstrained condition. The toe of the overriding plate kicks up and the shoreline drops...
