[Coral-List] response to tsunami at Kwajalein

Susan_White at fws.gov Susan_White at fws.gov
Sun Mar 20 16:06:07 EDT 2011

Tsunamis can impact atolls. Indeed, we just experienced significant impacts in Papahânaumokuâkea at two atolls: Midway Atoll National Wildlife Refuge and Kure Atoll (and likely Pearl and Hermes and Lisianski), as well as Laysan Island. There were no impacts further down the island chain at French Frigate Shoals/ Tern Island.  See the "tsunami information" link at http://www.fws.gov/midwayatoll. 

While it pales in comparison to the tragedies in Japan, at Midway Atoll NWR more than 110,000 albatrosses were lost (est. 22% of this year's cohort and a thousand adults) as well as an unknown number of burrow-nesting seabirds (likely tens of thousands).  Spit, Eastern and Sand islands (in Midway atoll) were overwashed 100%,  60% and 20% respectively. We don't yet know of damage to reefs and underwater. Losses at Kure will likely not be quantified since personnel were evacuated post tsunami.  The extent of wildlife and habitat impacts at other island/reef units of Papahânaumokuâkea where no personnel were stationed is unknown at this time (transportation to the sites is not available).

One thing we learned from this event is that we're all still learning about tsunamis.

Susan White, Project Leader
Pacific Reefs National Wildlife Refuge Complex
Email: susan_white at fws.gov 
ph: 808/792-9560 
><> ><> ><> ><> ><> ><> ><> ><> ><> ><> 
Pacific Remote Islands Marine National Monument:
Baker, Howland, Jarvis, Palmyra Atoll, Kingman Reef, Johnston Atoll, Wake Atoll NWRs
Rose Atoll Marine National Monument:
Rose Atoll NWR
Marianas Trench Marine National Monument:
Marianas Arc of Fire, Mariana Trench NWRs
><> ><> ><> ><> ><> ><> ><> ><> ><> ><> 
U.S. Fish & Wildlife Service
300 Ala Moana Blvd. Rm 5-231
Honolulu, HI 96850
fax: 808/792-9585
~ Susan 

----- Original Message -----
From: Don Baker [reefpeace at yahoo.com]
Sent: 03/19/2011 08:37 AM ZE8
To: Carly Kenkel <carly.kenkel at gmail.com>
Cc: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] response to tsunami at Kwajalein

Hi Carly,

Atolls have never (to my recollection) been affected by tsunami waves..but only storm generated waves from Typhoons. Why?  Well.....the tsunami is really a shock wave and rather deeply focused from its source event.  To try to note a case in point to demonstrate here was a tsunami that hit the Federated States of Micronesia island of Kosrae one evening near sunset.  This event happened maybe in the 1980s. (can someone assist in a date here from the FSM?).   My good friend, Roger Emerson was sitting on his back door step when he saw a wave about 2 feet high quickly run across the shallow reef flat and smack into the road causeway.  Being only about 2 feet high...no one really thought it was anything to be concerned about.  The next day, spearfisher men came back into towen and reported what they saw on the outer reef front.  The coral was totally ripped apart, huge porites colonies rolled over and the large acropora plate corals knocked about.

So what happened?   The depth issue is the key.  Atolls will get hit by the tsunami for sure but the wave may only be a foot or less high as it comes across the reef...and may never come across if its low tide. The small wave is the tsunami's top portion that skimmed off while the main shock wave hit the atoll's deep reef front wall. Tsunami waves are, again, deep shock waves.  The shock wave is most dangerous when the coastal region affected has relatively shallow off shore water. This allows the wave to build up and reach hts of 30 + feet.  Hawaii is typical as well as the coasts of Japan.  Guam is not like Hawaii and tsunami waves may hit but be very small as the water gets quite deep off shore in less then a mile.  The biggest waves I saw on Guam was during Typhoon Pamela down at the Uof Guam Marine Lab.....they were about 25 + feet high as they slammed the reef margin and then the tops racing across the shallows and slam into the jungle.


--- On Fri, 3/18/11, Carly Kenkel <carly.kenkel at gmail.com> wrote:

From: Carly Kenkel <carly.kenkel at gmail.com>
Subject: [Coral-List] response to tsunami at Kwajalein
To: coral-list at coral.aoml.noaa.gov
Date: Friday, March 18, 2011, 3:25 AM

Hi All -

In case anyone is interested - I've done some work on Kwaj and know one of
the principal dive instructors there.  I emailed him this past weekend and
he says Kwaj is fine.  He's always told me that Kwaj has never been affected
by major waves...out of curiosity, does anyone know why this might be the

And thanks Dean for all your efforts in monitoring reefs in the RMI!!!


Carly Kenkel
Graduate Student
Dept. of Integrative Biology
The University of Texas at Austin
Coral-List mailing list
Coral-List at coral.aoml.noaa.gov

Coral-List mailing list
Coral-List at coral.aoml.noaa.gov

More information about the Coral-List mailing list