TheThe IndonesianIndonesian EarthquakeEarthquake andand TsunamiTsunami LessonsLessons forfor thethe UnitedUnited StatesStates

Rupture zone of Rupture zone of 2004 Indonesian 1700 Cascadia Earthquake Earthquake

1000 km 1000 km Global distribution of earthquakes

INDIAN OCEAN

PACIFIC OCEAN

INDIAN OCEAN

ATLANTIC OCEAN NORTON MEDIA LIBRARY, 2001

M 9.3 December 26, 2004 earthquake Cascadia subduction zone Uplift Uplift Subsidence Breuh, 15 m water height VisualizingVisualizing inundationinundation

Lhoknga, 20 m water height

Jantang, 20 m water height VisualizingVisualizing inundationinundation

Debris in tree branches

Broken branches

How high was the wave? 7 Lori’s + elevation above sea level = 47 feet high

Lhokruet, April 2005 Photo, Bruce Jaffe, USGS Banda , Indonesia

Before , Indonesia

After Tsunami deposits 1964 1960

1700

Crescent Beach Motel, 1964 NorthNorth CoastCoast PlatePlate TectonicsTectonics Plan (map) View) Cross Section

UniqueUnique GeologicGeologic SettingSetting The Cape Mendocino earthquakes were located close to the Mendocino triple junction where three plates, the Gorda, the Pacific and the North American, meet.. SubsidenceSubsidence

GhostGhost ForestsForests

Photo by Guy Gelfenbaum, USGS USG Photo Calang, Copalis River, Washington

Trees killed by coastal subsidence Trees killed by the 1700 in the 2004 Indonesian earthquake. Cascadia earthquake. SurfaceSurface DeformationDeformation -- UpliftUplift

Nias Island, Indonesia Cape Mendocino, California

Clam beds uplifted above high tide Dead and dying reef communities in the 2004 Indonesian earthquake killed by the 1992 Cape Mendocino Earthquake Lessons from Indonesia ComparingComparing thethe AcehAceh coastcoast andand SimueleuSimueleu IslandIsland

JantangJantang

LangiLangi Lessons from Indonesia JantangJantang Village,Village, SumatraSumatra •• Waves arrived 20 minutes after the earthquake •• Tsunami height 45 - 60 ft •• 100% structures destroyed •• 2% of population survived NoNo oneone knewknew whatwhat toto do…do…

NoNo previousprevious awarenessawareness ofof tsunamistsunamis

Current Activities: removing debris, gathering coconuts, reclaiming family land Lessons from Indonesia LangiLangi Village,Village,SimuelueSimuelue IslandIsland •• Waves arrived 8 minutes after the earthquake •• Tsunami height 30 to 45 feet •• 100% structures destroyed •• 100% of population survived EveryoneEveryone knewknew toto immediatelyimmediately gogo toto highhigh ground.ground. OralOral historyhistory ofof 19071907 tsunamitsunami (Simuelue New homes built on foundation slabs of destroyed structures -- SmongSmong word for tsunami)

Current Activities: building boats, gardening, fishing. Still dependent upon aid but normal village life has resumed. Above, the new cattle were provided by aid organizations. WhatWhat If?If? We don’t know what the next Cascadia earthquake and tsunami will do to the North Coast. We can make a reasonable guess based on paleo-seismic studies, modeling, and what has happened in other tsunamis. Freshwater Lagoon

Scour

cars and debris

Before After ? Freshwater Lagoon: A tsunami could sweep over the sand spit, destroying Highway 101 and knocking cars and debris into the lagoon. The tsunami may be strong enough to scrape trees and vegetation off the hillside to a height of more than 30 feet. Base image used with the permission of the Coastal Records Project