Cascadia Great Earthquake and Tsunami Suite
I The Great Sumatran Earthquake and
Tsunami of December 2004
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II Is the stage being set for a Great
Cascadian Earthquake and Tsunami?
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III The Search for Great Cascadian
Earthquakes and Tsunamis in the Past
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IV Impact of a Great Cascadian Earthquake
and Tsunami on one Coastal Community
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V Rupture on the Seattle Fault: A Case
Study
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Natural Hazard Case Studies
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Unit V. Earthquake Hazard in a Cascadian Metropolis: Seattle
This unit involves investigations of earthquake and tsunami hazard in a major Cascadian metropolis, the City of Seattle. Investigations focus on hazard associated with a system of active thrust faults collectively called the Seattle Fault Zone, which passes directly through the city.
The Seattle Fault Zone is a manifestation of active plate tectonic processes. Students analyze the large-scale plate tectonic framework by investigating the present-day relative motions of the North American, Juan de Fuca, and Pacific plates in a GIS; they then learn how the plate configurations have evolved over the past 40 m.y.
Students view the present-day distribution of the horizontal component of relative ground motion based on precision GPS data and discover how shallow cross-cutting thrust fault systems—in particular the Seattle Fault Zone—can be explained by the jostling of discrete crustal blocks within the overall plate tectonic framework.
Students carry out investigations of seismic hazard in relation to the geography and cultural features of Seattle using Google Earth. A Google Earth.kmz file contains particular views and data layers specifically developed for the unit. Students will pan, zoom, and fly to various locations using Google Earth tools.
Students turn on a layer showing the strands of the Seattle Fault Zone and note that the northern strand passes just south of the city center. They then turn on a layer showing the distribution of the zones of potential liquefaction in relation to the city and the fault strands. They receive a tutorial about the phenomenon of liquefaction in terms of potential damage to built structures due to earthquake shaking. They then zoom to the Seattle Downtown area and examine the position of the fault strands and liquefaction zones in relation to this part of town. They take a close look at Harbor Island, the principal port facility, which was built on filled land, and speculate about the likely consequences of a major earthquake. They analyze a NOAA model animation of Harbor Island and much of city adjacent to Puget Sound being overrun by an earthquake-generated tsunami.
They take a close look at the Alaskan Way Viaduct, a major elevated freeway adjacent to Puget Sound built long before there was any awareness of earthquake hazard. As a finale to the Google Earth section, students examine modeled peak ground acceleration associated with a scenario M7+ earthquake on the Seattle Faults Zone and note the zone of extreme shaking with respect to Seattle as a whole and the particular cultural features they have been examining.
Students carry out a series of quantitative investigations using GIS tools of how a number of key cultural features and infrastructural “lifelines” are distributed with respect to the zone of highest modeled peak ground acceleration for a M7+ scenario earthquake: population density, roadways, bridges, harbors, and schools. They then speculate on possible consequences to other lifelines: railroads, gas lines, and sewer lines.
Download project files now...
ArcGIS version
MyWorld GIS version
This material is based upon work supported by the National Science Foundation under Grant Number DUE-0521936. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
This unit involves investigations of earthquake and tsunami hazard in a major Cascadian metropolis, the City of Seattle. Investigations focus on hazard associated with a system of active thrust faults collectively called the Seattle Fault Zone, which passes directly through the city.
The Seattle Fault Zone is a manifestation of active plate tectonic processes. Students analyze the large-scale plate tectonic framework by investigating the present-day relative motions of the North American, Juan de Fuca, and Pacific plates in a GIS; they then learn how the plate configurations have evolved over the past 40 m.y.
Students view the present-day distribution of the horizontal component of relative ground motion based on precision GPS data and discover how shallow cross-cutting thrust fault systems—in particular the Seattle Fault Zone—can be explained by the jostling of discrete crustal blocks within the overall plate tectonic framework.
Students carry out investigations of seismic hazard in relation to the geography and cultural features of Seattle using Google Earth. A Google Earth.kmz file contains particular views and data layers specifically developed for the unit. Students will pan, zoom, and fly to various locations using Google Earth tools.
Students turn on a layer showing the strands of the Seattle Fault Zone and note that the northern strand passes just south of the city center. They then turn on a layer showing the distribution of the zones of potential liquefaction in relation to the city and the fault strands. They receive a tutorial about the phenomenon of liquefaction in terms of potential damage to built structures due to earthquake shaking. They then zoom to the Seattle Downtown area and examine the position of the fault strands and liquefaction zones in relation to this part of town. They take a close look at Harbor Island, the principal port facility, which was built on filled land, and speculate about the likely consequences of a major earthquake. They analyze a NOAA model animation of Harbor Island and much of city adjacent to Puget Sound being overrun by an earthquake-generated tsunami.
They take a close look at the Alaskan Way Viaduct, a major elevated freeway adjacent to Puget Sound built long before there was any awareness of earthquake hazard. As a finale to the Google Earth section, students examine modeled peak ground acceleration associated with a scenario M7+ earthquake on the Seattle Faults Zone and note the zone of extreme shaking with respect to Seattle as a whole and the particular cultural features they have been examining.
Students carry out a series of quantitative investigations using GIS tools of how a number of key cultural features and infrastructural “lifelines” are distributed with respect to the zone of highest modeled peak ground acceleration for a M7+ scenario earthquake: population density, roadways, bridges, harbors, and schools. They then speculate on possible consequences to other lifelines: railroads, gas lines, and sewer lines.
Download project files now...
ArcGIS version
MyWorld GIS version
This material is based upon work supported by the National Science Foundation under Grant Number DUE-0521936. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.