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, Indonesia April 2005 Photo, Bruce Jaffe, USGS Banda Aceh, Indonesia
Before Banda Aceh, 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,Sumatra 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