tsunamis!. tsunamis caused by vertical displacement of water seismic sea waves not tidal waves, not...
Post on 04-Jan-2016
215 Views
Preview:
TRANSCRIPT
Tsunamis! Tsunamis!
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
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 Times to Hawaii
Source: After U.S. Geological Survey.
Tsunami Damage in Kodiak, Alaska
Source:Photograph courtesy of National Geophysical Data Center.
TsunamisTsunamis
• Early warning systems
• Pacific: – Established in 1948, 2 years after Hawaii
was hit by a tsunami
• Atlantic– Can easily reach 15 m in height
• Indian Ocean– No early warning system until 2005
Source: http://www.prh.noaa.gov/pr/ptwc/bulletins.htm
Indonesia, Dec. 2004Indonesia, Dec. 2004
http://www.globalsecurity.org/military/world/thailand/images/ik_crisp_khao_lak_10.jpg
http://www.globalsecurity.org/military/world/thailand/images/ik_crisp_khao_lak_10.jpg
Source: http://homepage.mac.com/demark/tsunami/
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
Alaska, 1958
Puerto Rico, 1918 Earthquake: 7.5
Source: http://www.usc.edu/dept/tsunamis/caribbean/webpages/index.html
Death toll: 116
Tsunami (40) Aquadilla (32)
Source: http://www.usc.edu/dept/tsunamis/caribbean/webpages/index.html
Source: http://www.usc.edu/dept/tsunamis/caribbean/webpages/index.html
top related