| HOW DOES THE CHANGING EARTH'S SURFACE AFFECT SOCIETY?
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Landslides occur in all 50 states and claim 25 - 50 lives a year. The U.S. National Research Council (Committee on Ground Failure Hazards, 1985) estimated that landslides cause between $1.6 billion and $3.2 billion in damage (rates adjusted for inflation) in the U.S. each year.[2] Land subsidence also poses problems for society. Parts of the city and port of Long Beach, California, suffered major problems due to rapid (up to 0.75 m yr-1) land subsidence related to extraction of oil from the underlying Wilmington oil field. Problems were caused by both inundation due to vertical motion and by horizontal strains on the sides of the subsidence bowl. Total subsidence in Long Beach reached as much as 9 m before the land surface was stabilized by an integrated program of fluid injection to balance the extraction. The amount of subsidence at Long Beach was close to linearly proportional to the amount of petroleum extracted. Subsidence over petroleum extraction zones can also cause significant damage to extraction infrastructure itself, including expensive well failures.
The Lost Hills oil field in central California suffers rapid ground subsidence due to compaction of the oil reservoir. Click here for MPEG video of the Lost Hills oil field (5 MB). Monitoring the subsidence is essential for understanding the deformation of the reservoir rocks and for optimizing the operation of the oil field to mitigate the compaction. The rapid and time-varying subsidence at Lost Hills provides a strong signal for testing and measuring the error characteristics of several types of elevation change technologies, which can then be used for other applications. The interaction between climate and tectonics can also affect society. The Great Flood of 1993 impacted 9 states, causing 48 deaths, and damaging or destroying at least 50,000 homes. Over 15 million acres of farmland were inundated and 54,000 people were evacuated from their homes. The total damage and costs from the Great Floods of 1993 exceeded $21 billion.[3] According to the National Weather Service, the Great Flood actually began in 1992 when rain and snow saturated the soil. The wet winter was followed by excessive rain in the spring and summer, causing, from June to August of 1993, one of the largest floods in history. The flooding of dozens of rivers, including the Mississippi and Missouri rivers and eventually lead to the inundation of 9 states. Because of the saturated soil, the flood waters did not properly drain for nearly 200 days.[4] The Great Flood of 1993 was the mostly costly flood in the history of the United States. Annually, floods cause an average loss of $3.5 billion and 140 fatalities in the United States.[3] Most deaths are related to flash floods- an especially high percentage of the fatalities occur when people try to drive through waters over 1 foot deep. If flood-prone areas can be adequately targeted, then educational outreach and evacuation plans can be implemented before flash floods strike. Flash floods occur within a few minutes or hours of excessive rainfall or sudden release of water. Flash floods, sometimes with heights over 30 feet, can tear out trees, carry boulders, destroy buildings and bridges, and rip through landscapes, forming new channels.[5] Long term climate studies, more accurate elevation and flood maps, more frequent monitoring of river water levels, vegetation cover, land use patterns, water routes, fire history, and topography can all lead to better understanding of floods, more accurate flood forecasting and models. Direct losses of such natural hazards include: repair, rebuilding or replacement public and private property. According to the USGS, indirect costs include:
Expected Accomplishments:
Practical Benefit to Society:
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References: [1] "Socioeconomic & Enviromental Impact of Landslides in the Western Hemisphere," U.S. Geological Survey Open-File Report 01-0276 by Robert L. Schuster and Lynn M. Highland, http://geology.cr.usgs.gov/pub/open-file-reports/ofr-01-0276/ [2] "Report on Landslides- Damages, Costs & Casualties," U.S. Geological Survey, 2001 http://geology.cr.usgs.gov/pub/open-file-reports/ofr-01-0276/ [3] "Billion Dollar U.S. Weather Disasters, 1980-2001," National Climatic Data Center - January 1, 2002 http://lwf.ncdc.noaa.gov/oa/reports/billionz.html [4] "A New Evaluation of the USGS Streamgaging Network--A Report to Congress," USGS http://water.usgs.gov/streamgaging/network.html#HDRflooding [5] NOAA, see reference #2 [6] "National Oceanic and Atmospheric Administration Climate-Watch," National Climatic Data Center - September, 2001 http://lwf.ncdc.noaa.gov/oa/climate/extremes/2001/august/extremes0801.html |
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The
changing Earth's surface affects society through landslides, land
subsidence, floods and other natural hazards. These disasters can
be both deadly and costly to society: the
Thistle landslide was the most costly single landslide event in
U.S. history with costs exceeding $400 million. Land began shifting
in Thistle, Utah in 1983 because of groundwater buildup from heavy
rains during the previous fall and the melting of deep snowpack
from the winter. Within a few weeks, the landslide dammed the Spanish
Fork River, destroying U.S. Highway 6 and the main line of the Denver
and Rio Grande Western Railroad. The landslide dam caused flood
waters to rise which in turn led to lead the inundation of the surrounding
area. The town of Thistle was completely obliterated.[1]
