Larry Braile, [email protected], web.ics.purdue.edu/~braile
Sheryl BraileCSTA/NSTA, Long Beach,CA, December 4-6, 2014
(Despite the popularity of this image, tsunami waves do not normally look like this, especially in the open ocean)
Tsunami! Understanding the Generation, Propagation, and
Hazards of Tsunamis
This PowerPoint Presentation (last modified December, 2014):http://web.ics.purdue.edu/~braile/edumod/tsunami/Tsunami!.ppt
Tsunamis can be generated by:1. Large Earthquakes (megathrust events
such as Sumatra, Dec. 26, 2004; Japan, Mar. 11, 2011)
2. Underwater or near-surface volcanic eruptions (Krakatoa, 1883)
3. Comet or asteroid impacts (evidence for tsunami deposits from the Chicxulub impact 65 mya)
4. Large landslides that extend into water (Lituya Bay, AK, 1958)
5. Large undersea landslides (evidence for prehistoric undersea landslides in Hawaii and off the east coast of North America)
Schematic plate tectonic setting for tsunami
generation
NOAACommonly, in mega-thrust earthquakes, a
very large area of the ocean floor is uplifted
TRENCH
Earthquake generation of tsunami(note: tsunami wave in the animation shouldbe asymmetrical with a first peak traveling to the left and a first trough traveling to the right)
http://ffden-2.phys.uaf.edu/645fall2003_web.dir/elena_suleimani/generation_small.movhttp://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm
Animation
Modified from: http://unesdoc.unesco.org/images/0018/001898/189842e.pdf
Ocean floor dragged down (friction)
Ocean floor bowed up (elastic bending)
Rebound with fault slip
Peak Trough
Plate Motion
Side View
Table
Cardboard Foam
Table
Subduction of Plate at Convergent Boundary
http://web.ics.purdue.edu/~braile/edumod/foammod/foammod.htmhttp://web.ics.purdue.edu/~braile/edumod/foammod/foammod.pdf
Illustrating the positive and negative pulses of the tsunami wave produced by a subduction zone earthquake Lithosphere bows up
here prior earthquake slip due to elastic bending
Lithosphere dragged down here due to
friction between the upper and lower
plates
Exploring Planet Earth
Blind Thrust Fault Earthquake Rupture Animation (Northridge, 1994)Brad Aagaard, USGS
http://pasadena.wr.usgs.gov/office/baagaard/research/animations/animations.htmlThe fault rupture will be visible in the animation. Displacements (magnified 3000
times) will be visible by the movement of the mesh from the model. The amplitude of motions and seismic waves is color coded according to ground velocity.
Note the rupture along the fault over time from the deepest extent of the fault.
http://web.ics.purdue.edu/~braile/new/AagaardBlindThrustAnimation.ppt
Blind Thrust Fault Earthquake Rupture Animation – Brad Aagaard, USGS
http://pasadena.wr.usgs.gov/office/baagaard/research/animations/animations.htmlThe fault rupture will be visible in the animation. Displacements (magnified 3000
times) will be visible by the movement of the mesh from the model. The amplitude of seismic waves is color coded according to ground velocity.
http://pasadena.wr.usgs.gov/office/baagaard/research/animations/animations.html
Earthquake Rupture
Descriptor Magnitude Average Annually
Great 8 and higher 1 ¹
Major 7 - 7.9 17 ²
Strong 6 - 6.9 134 ²
Moderate 5 - 5.9 1319 ²
Light 4 - 4.9 13,000 (est.)
Minor 3 - 3.9 130,000 (est.)
Very Minor 2 - 2.9 1,300,000 (est.)
¹ Based on observations since 1900. ² Based on observations since 1990.
Worldwide earthquakes per year (from USGS):
Worldwide earthquakes per year:
Frequency-magnitude relationship suggests that magnitude 9+ events will occur about once per decade, statistically; since 1900, the actual number is ~once per 20 years.
Tsunami Statistics (NOAA): http://wcatwc.arh.noaa.gov/tsustats.pdf
Tsunami Statistics (NOAA): http://wcatwc.arh.noaa.gov/tsustats.pdf (Dec. 26, 2004 tsunami, over 250,000 deaths; Jan. tsunami, over 18,000 deaths)
Tsunami Statistics
Tsunami wave propagation characteristics – note that as water depth becomes smaller, waves slow down, become shorter wavelength (), and have larger amplitude.
When the water is 10 m deep, what is the separation of the waves in minutes? (hint: t = v)
NOAA
Animation courtesy of Dr. Dan Russell, Kettering University
http://www.gmi.edu/~drussell/demos.html
Water waves animation
Direction of propagation
Tsunami velocity and amplitude equations
(These are plane layer [flat ocean bottom] equations)
1. Wave velocity controlled by water depth:
v = (g x d)1/2 where v is velocity, d is water depth and g is the acceleration of gravity = 9.8 m/s2; so, velocity decreases in shallower water.
2. Wave height (amplitude) increases (conservation of energy) in shallow water:
AS = AD x (VD/VS)1/2 where AS = amplitude in shallow water, AD = amplitude in deep water, VS = velocity in shallow water, and VD = velocity in deep water.
Geist, Titov and Synolakis, Tsunami: Wave of Change, Scientific American, January, 2006.
Wave Heights – Satellite observation versus calculated model – open ocean, deep water
~1600 km; ~2.2 hours of waves at 750 km/hr
Tsunami Wave Tank1. “SnapLock Select” plastic underbed storage box 118 x 51 x 13 cm (45” x 21” 5”) from Walmart, K-Mart, etc. (or Sterilite #1996, 74 qt.), remove handles, fill holes with silicon sealer.2. Plexiglass 53 x 48 x 0.5 cm (21” x 19” x 3/16”) [could use sand for “coastal area” instead of plexiglass].3. Two 30 cm plastic rulers with clay base, 30 cm apart.4. Fill to 8 cm deep with water.
Tsunami Wave Tank http://www.target.com/p/Sterilite-74-qt-Ultra-Storage-Box-White/-/A-10497010
Tsunami Wave Tank (close-up of ruler and plexiglass – note slope representing shallowing of water depth adjacent to coast)
Tsunami Wave Tank – Video of Wave TankDownload Tank.mov from:
http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm
Tsunami Wave Tank – Video of Waves
Water Drop – Point source, circular spreading of energy:
Download WaterDrop3.mov and WaterDrop4Measure.mov from:http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm
1. What are the characteristics of the wavesgenerated by the water drop?2. Measure the velocity of the wave using a stopwatch (distance from center to side of tank in cm, divided by timein seconds).3. Can you observe reflectedwaves.4. Why do the waves eventually disappear?
Tsunami Wave Tank – Video of Waves
Line Source (plane wave) – No spreading of energy:
Download PlaneWave1.mov from:http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm 1. What are the
characteristics of the wavesgenerated by the line source?2. Measure the velocity of the wave using a stopwatch (follow one wave crest from firstruler to the second – 30 cm divided by time).3. What is the wave height?4. What is the wave length?5. Do the waves get smallerwith distance of propagation?6. What type of water wave inthe ocean is similar to thesewaves?
Ocean Waves
Tsunami Wave Tank – Video of Waves
Tsunami – Line source and entire water column disturbed:
Download Tsunami2.mov from:http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm 1. What are the characteristics
of the waves generated by the tsunami source?2. Measure the velocity of the wave using single frame advance (follow one wave crest from firstruler to the second – 30 cm divided by time).3. What is the wave height?4. What is the wave length?5. What happens to the wave as it propagates into shallow water?
Tsunami Wave Tank – Video of Waves
Tsunami – Line source and entire water column disturbed:
Download Tsunami4Measure.mov from:http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm
(Use pause and single frame advance to observe wave characteristics)
~5.8 s ~6.2 s
Note Long Wavelength Note Wave Cresting
Tsunami Wave Tank Materials
Wave generation sources; drop into water or oscillate up and down on water surface to create waves: Golf ball, plastic golf ball (or table tennis ball), eye dropper, clay, wood, styrofoam strips
48 x 10 x 2.5 cm(19” x 3.75” x 1”)
Geist, Titov and Synolakis, Tsunami: Wave of Change, Scientific American, January, 2006.
26 Dec. 2004 Tsunami max. wave height and arrival time
Seismic Eruption software: http://www.geol.binghamton.edu/faculty/jones/ Indonesia area historical earthquakes files, download from:http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm
Seismic Eruption software: http://www.geol.binghamton.edu/faculty/jones/ Sumatra earthquake and aftershocks files, download from:http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm
Tsunami simulation(Note: wave trough is first arriving energy propagating to the East, and focusing of energy to west and east of the earthquake rupture area)
http://staff.aist.go.jp/kenji.satake/animation.gif
Chedi Resort,Phuket, Thailand, wave height ~4+ m (?, from estimates of water level from beach umbrellas on grassy area above the beach)
Tilly Smith and the Dec. 26, 2004 Sumatra tsunami, Phuket, Thailand (about 10,000 people were killed by the tsunami in Thailand; Tilly is credited with saving the lives of about 100 people because she recognized the warning signs of an oncoming tsunami.
http://en.wikipedia.org/wiki/Tilly_Smith
http://news.nationalgeographic.com/news/2005/01/0118_050118_tsunami_geography_lesson.html
https://www.youtube.com/watch?v=6C3CJX1-d_8&spfreload=10
http://nalakagunawardene.com/2007/10/10/geography-lesson-that-saved-many-lives-the-story-of-tilly-smith/
“Tilly Smith learned about tsunamis in a geography lesson two weeks before the tsunami from her teacher Andrew Kearney at Danes Hill School in Oxshott, Surrey. She recognised the symptoms of receding water from the shoreline and frothing bubbles on the surface of the sea and alerted her parents, who warned others on the beach and the staff at the hotel on Phuket, where they were staying. The beach was evacuated before the tsunami reached shore, and was one of the few beaches on the island with no reported casualties.” (http://en.wikipedia.org/wiki/Tilly_Smith)
Up to 10 m high tsunami waves hit coastal area near Up to 10 m high tsunami waves hit coastal area near Sendai, in northern Honshu, JapanSendai, in northern Honshu, Japan
Tohoku, Japan tsunami, March 11, 2011
Tohoku, Japan Earthquake: Aftershock (and Foreshock) Sequence, 03/08/11 - 03/16/11
Note that the magnitudes of the 2011/03/11 06:15 (Mw 7.9) and 2011/03/11 06:25 (Mw 7.7) aftershocks were updated from earlier, lower estimates. Updates occurred on 03/16 and 03/18, respectively.
Kahului, Maui Tide data, March 8 – March 10, 2011 GMT
Predicted Observed
Difference
(http://tidesandcurrents.noaa.gov/index.shtml, http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Tide+Data)
Max. Amplitude ~ 0.3 meters
Tides
Kahului, Maui Tide data, March 11, 2011 GMT
PredictedObserved
Difference
Tsunami (+/- 2 m waves, ~ 30 minute period)
Max. Amplitude ~ 2.0 meters
Kahului, Maui Tide data, February 18 - March 20, 2011 GMT
Predicted Observed
Difference
Tsunami (still propagating through Pacific Ocean 7 days later)
Max. Amplitude ~ 2.0 meters
Tides
Tsunami Videos:Tsunami wave spills over seawall, smashes boats, cars http://www.youtube.com/watch?v=5-zfCBCq-8I&feature=player_embedded#at=22
Massive Quake Triggers Tsunami in Japanhttp://www.youtube.com/watch?v=1XpSLiPHLPk&feature=player_embedded
Japan Earthquake 3.11.2011 - Tsunami hits http://www.youtube.com/watch?v=s8L2kikyVzk&feature=player_embedded
TSUNAMI SENDAI AIRPORT (JAPAN 3/11/11) http://www.youtube.com/watch?v=k6agTZo3E5Y&feature=related
First tsunami waves hit Hawaii islands, California coast after Japan 2011 earthquake http://www.youtube.com/watch?v=FEeHkr5ew3c&feature=related
Crescent City CA March 11 2011 Tsunami Time Lapse videohttp://www.youtube.com/watch?v=ai6pPk0VHDY
Crescent City Takes Tsunami Toll http://www.youtube.com/watch?v=SPqCX1FUdU0
Tsunami rocks boats in Santa Cruz harborhttp://www.youtube.com/watch?v=cswolureeF4
Wall of Water Slams Japanese Townhttp://news.yahoo.com/video/world-15749633/wall-of-water-slams-japanese-town-24518186
Kailua Kona Tsunami Time Lapse 2011 Bay Fronthttp://www.youtube.com/watch?v=YjCV182S5y4&feature=player_embedded
Japanese Earthquake Tsunami Wave arrives in Emeryville CAhttp://www.youtube.com/watch?v=jdMDCLwblkY&feature=player_embedded
Tsunami Damage Near Sendai
Tsunami Near Sendai Airport
Tsunami Damage from the Tohoku [Northern Honshu, Japan] M9.0 Earthquake of March 11 – Satellite View before Tsunamihttp://www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html
Tsunami Damage from the Tohoku [Northern Honshu, Japan] M9.0 Earthquake of March 11 – Satellite View after Tsunamihttp://www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html
Tsunami Damage from the Tohoku [Northern Honshu, Japan] M9.0 Earthquake of March 11 – Satellite View before Tsunamihttp://www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html
Tsunami Damage from the Tohoku [Northern Honshu, Japan] M9.0 Earthquake of March 11 – Satellite View after Tsunamihttp://www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html
Some other recent tsunamis that have impacted the western U.S.
1946 Aleutian Islands earthquake (M8.6)
Tsunami wave heights and fatalities: Oregon and California – Coo’s Bay (~3 m), Ft. Bragg (~2-3 m), Half Moon Bay (~3-4 m), Muir Beach (~4 m), Santa Cruz (~3 m, one death). Hawaiian Islands – (6-7 waves, ~15 minute period, ~8-16 m, 159 deaths, mostly in Hilo).
1964 Aleutian Islands earthquake (M9.2)
Tsunami wave heights and fatalities: Seaside, Oregon (3-4 m, 4 deaths, Crescent City, California (6 m), 12 deaths in California.
http://www.usc.edu/dept/tsunamis/alaska/1946/webpages/index.htmlhttp://www.usc.edu/dept/tsunamis/alaska/1964/webpages/index.html
http://www.usc.edu/dept/tsunamis/alaska/1946/webpages/; http://www.aeic.alaska.edu/quakes/Alaska_1964_earthquake.html
M9.2 1964 Alaska earthquake
M8.6 1946 Aleutians earthquake
http://en.wikipedia.org/wiki/1700_Cascadia_earthquake
Evidence for Cascadia tsunami: The Orphan Tsunami of 1700 (published 2005, Brian Atwater and others)
Other sources of tsunamis for western U.S.
The Cascadia subduction zone is likely the source area for a tsunami that struck Japan in the year 1700.
Comparison of the size aftershock zone for the 2004 Sumatra earthquake with the Cascadia subduction zone
http://en.wikipedia.org/wiki/1700_Cascadia_earthquake
“A simulated tsunami reaches Japan ten hours after its start along the Pacific coast of North America” (http://pubs.usgs.gov/pp/pp1707).
http://pubs.usgs.gov/pp/pp1707/pp1707.pdf
Tsunami simulation for megathrust earthquake in Cascadia impacting Japan, and other locations on the Pacific ocean basin (http://pubs.usgs.gov/pp/pp1707).
Earthquake and Tsunami Safety• Earthquake safety – “Duck and cover”.
• Tsunami safety (when in a coastal, near-sea-level area; two situations: local EQ or distant EQ):
• If you feel strong shaking for 15+ seconds; after shaking, move to higher ground.
• If there is a tsunami warning, or if you observe unusual waves (appear to be large and rapid tidal changes, or water recedes), move to higher ground.
• Do not return until event is over; a tsunami includes multiple waves sometimes separated
by 10-30 minutes and may last for hours.
Tsunami Teacher Resource Kit (17 MB pdf) from ITIC (International Tsunami Information Centre) http://www.tsunamiwave.info/
Tsunami Teacher Resources
IRIS Posters: http://www.iris.edu/about/publications.htm#p
Larry Braile, [email protected], web.ics.purdue.edu/~braile
Sheryl BraileCSTA/NSTA, Long Beach,CA, December 4-6, 2014
(Despite the popularity of this image, tsunami waves do not normally look like this, especially in the open ocean)
Tsunami! Understanding the Generation, Propagation, and
Hazards of Tsunamis
This PowerPoint Presentation (last modified December, 2014):http://web.ics.purdue.edu/~braile/edumod/tsunami/Tsunami!.ppt