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

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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 bwashom@ucsd.edu

The End