Waves
Tsunamis!Tsunamis!
2005331749975
TsunamisTsunamis
•Caused by vertical displacement of water
•Seismic sea waves
•Not tidal waves, not caused by wind
•Appear small in the open ocean
•Grow in size in shallow water
–Can easily reach 15 m in height
•Can travel ~1000 km/hr
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Tsunami WavesTsunami Waves
•Long periods (p) and wavelengths (wl)
–Wind-waves: p = 10 min, wl = 150 m
–Tsumanis: P = 1 hr, wl = 100 km
–Waves have a trough and a crest
•Appear small in the open ocean
•Grow in size in shallow water
–Can reach >15 m in height
•Travel ~1000 km/hr
•Can travel around the world quickly
Tsunami Travel Timesto Hawaii
Source: After U.S. Geological Survey.
Tsunami Damage in Kodiak, Alaska
Source:Photograph courtesy of National Geophysical Data Center.
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TsunamisTsunamis
•Early warning systems
•Pacific:
–Established in 1948, 2 years after Hawaiiwas hit by a tsunami
•Atlantic
–Can easily reach 15 m in height
•Indian Ocean
–No early warning system until 2005
Earthquake epicenter,time and historical earthquake data.
Source: http://www.prh.noaa.gov/pr/ptwc/bulletins.htm
tsunami-bayofbengal
Indonesia, Dec. 2004Indonesia, Dec. 2004
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http://www.globalsecurity.org/military/world/thailand/images/ik_crisp_khao_lak_10.jpg
ik_crisp_khao_lak_10
http://www.globalsecurity.org/military/world/thailand/images/ik_crisp_khao_lak_10.jpg
2a
2b
3a
3b
4a
4b
12a
12b
Source: http://homepage.mac.com/demark/tsunami/
17a
17b
Source: http://homepage.mac.com/demark/tsunami/
Alternative causesAlternative causes
•Oceanic volcanoes
–Collapse of part of the volcano
•Landslides
–Mass
•Meteorite Impacts
–High energy impact from space
lituya
Alaska, 1958
prmap_web
Puerto Rico, 1918 Earthquake: 7.5
Source: http://www.usc.edu/dept/tsunamis/caribbean/webpages/index.html
prphoto_1
Death toll: 116
Tsunami (40) Aquadilla (32)
Source: http://www.usc.edu/dept/tsunamis/caribbean/webpages/index.html
prphoto_2
Source: http://www.usc.edu/dept/tsunamis/caribbean/webpages/index.html