washom tsunami impacts on midway atoll 3 11-11 abbreviated version
DESCRIPTION
Abbreviated version of seminar provided to Scripps Insitution of Oceanography by Byron Washom on 4-6/11 on the impacts of the 3-11-11 Honshu Tsunami on Midway Atoll.TRANSCRIPT
Midway Atoll Natural Wildlife RefugePapahānaumokuākea
Marine National Monument
Impacts of Honshu TsunamiMarch 10-11, 2011
Byron Washom, UC San Diego
Presented at
Scripps Institution of Oceanography
April 6, 2011
The oldest known free-flying bird in US, ~ 60, an albatross named “Wisdom”, hatches her chick
• Advanced age may be double or triple the expected life span for a Laysan albatross,
• Oldest wild specimen documented during the 90-year history of the U.S. and Canadian bird-banding research program.
• She was first tagged with an identification band at ~5 in 1956 while incubating an egg.
• She has logged about 3 million flying miles (4.8 million mile (~six round trips to the Moon).
March 10-11, 2011 Honshu Tsunami
• http://freevideocoding.com/flvplayer.swf?file=http://flash.vx.roo.com/streamingVX/63056/1458/20110311_japan_wave_successions_sky_1000k.mp4&autostart=true
NOAA Animation
• http://www.youtube.com/watch?v=z9pXHlOtRTY
Bathymetry of Midway Atoll
History of Ocean Crossing Tsunamis
• Few observations, despite the five great ocean-crossing tsunamis of the 20th century.
• The believed highest value was at Midway in 1952, when runup reached 1.9 meters from the magnitude 9 Kamchatka earthquake, and Midway was square in the center of the radiated beam and only 3000 km from the source.
• Johnston Atoll, another atoll extensively modified by dredging, where the Chile tsunami of 1960 had a runup of 0.7 meters.
• Of atolls not extensively modified to handle shipping, the highest runup believed is Kiritimati in 1960, which recorded a runup of 0.3 meters.
Source: Gerard Fryer at the NOAA Pacific Tsunami Warning Center
Why should the hazard be so low?
• The sea level has risen since the last glaciation, and for the last 18,000 years, coral has been growing almost vertically upwards.
• As a consequence, each atoll in the Pacific has very steep upper slopes, making the island look pretty much like a spar buoy to the approaching tsunami.
• Unless man has modified the atoll, runup seems to be a factor of two from the height of the tsunami on the open ocean compared to a factor of five or six for open coasts on high islands.
• High islands have a tremendously reduced hazard if they have reefs
• By contrast, in 1960 Hawaii saw about 3 meters on open coasts without focusing and numerous locations where runup approached 10 meters (in Hilo runup reached 11 meters and 61 people died).
Source: Gerard Fryer at the NOAA Pacific Tsunami Warning Center
-1
-0.5
0
0.5
1
1.5
2
10:2
410
:26
10:2
810
:30
10:3
210
:34
10:3
610
:38
10:4
010
:42
10:4
410
:46
10:4
810
:50
10:5
210
:54
10:5
610
:58
11:0
011
:02
11:0
411
:06
11:0
811
:10
11:1
211
:14
11:1
611
:18
11:2
011
:22
11:2
411
:26
11:2
811
:30
11:3
211
:34
11:3
611
:38
11:4
011
:42
11:4
411
:46
11:4
811
:50
11:5
211
:54
Met
ers
NOAA Tidal Data: Midway 3-11-11
90 Minute elapsed time
Estimated Loss of Life
• 110,000 Albatross chicks died out of 450,000 nesting pairs, impact will be most evident in 4-5 yrs when this vintage will begin mating
• 2,000 adult Albatross• Virtually all underground nesting Bonin Petrils
that were located in the overwash zone• Majority of plant life where seawater inundation• The first chick from a mating pair of Short Tail
Albatross survived tsunami and 2 winter storms• Minimal documented loss of marine life
Kure and Laysan Evacuees
Photo Credits to
• Chris Jordan www.midwayjouney.com• Jan Vozenilek www.janvozenilek.com• Wayne Sentman
http://web.mac.com/naturefinder• Peter Leary http://peteatmidway.blogspot.com/• Mike Daak www.midway-island.com• James Watt http://www.wattstock.com/• Ku`uipo Rossiter • Byron Washom [email protected]
The End