Land Subsidence: Causes, Detection, and the Wilmington Oil Field, Long Beach
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Land Subsidence:
Causes, Detection, and the Wilmington Oil Field, Long Beach
Land subsidence is a major predicament in many areas of the United State and occurs for many reasons. Land subsidence is the gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials, usually with little or no horizontal movement (Galloway et al.).
Subsidence hazards involve either the sudden collapse of the ground to form a depression or the slow subsidence or compaction of the sediments near the Earth 's surface. Sudden collapse events are hardly ever major disasters, not anywhere near the scale of earthquakes, volcanoes, or landslide disasters, but the slow subsidence of areas causes much economic damage in the long run (Nelson). Natural and human-induced land subsidence across the United States has affected more than more than 17,000 square miles (44,000 square kilometers) in 45 States, an area roughly the size of New Hampshire and
Vermont combined, and is estimated to cost $168 million annually from flooding and structural damage, with the actual cost significantly higher due to unseen costs. The major causes of subsidence are: aquifer system compaction, drainage of organic soils, underground mining, hydrocompaction, sinkholes, and thawing permafrost (Galloway et al. and InSAR Workshop Summary Report). Recently, detection of subsidence areas is determined by Interferometric Synthetic Aperture Radar, InSAR. This technique is beneficial in determining minute changes in ground topography. Furthermore, the case study of subsidence in the Wellington Oil Field in Long Beach, CA. is of great interest in the study of subsidence and remediation measures.
The first cause of subsidence is aquifer system compaction, which is the compaction of unconsolidated aquifer systems accompanying excessive ground-water pumping (Galloway et al., 2009).
This is by far the major cause of land subsidence in the United States. The
Land Subsidence:
Causes, Detection, and the Wilmington Oil Field, Long Beach
Land subsidence is a major predicament in many areas of the United State and occurs for many reasons. Land subsidence is the gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials, usually with little or no horizontal movement (Galloway et al.).
Subsidence hazards involve either the sudden collapse of the ground to form a depression or the slow subsidence or compaction of the sediments near the Earth 's surface. Sudden collapse events are hardly ever major disasters, not anywhere near the scale of earthquakes, volcanoes, or landslide disasters, but the slow subsidence of areas causes much economic damage in the long run (Nelson). Natural and human-induced land subsidence across the United States has affected more than more than 17,000 square miles (44,000 square kilometers) in 45 States, an area roughly the size of New Hampshire and
Vermont combined, and is estimated to cost $168 million annually from flooding and structural damage, with the actual cost significantly higher due to unseen costs. The major causes of subsidence are: aquifer system compaction, drainage of organic soils, underground mining, hydrocompaction, sinkholes, and thawing permafrost (Galloway et al. and InSAR Workshop Summary Report). Recently, detection of subsidence areas is determined by Interferometric Synthetic Aperture Radar, InSAR. This technique is beneficial in determining minute changes in ground topography. Furthermore, the case study of subsidence in the Wellington Oil Field in Long Beach, CA. is of great interest in the study of subsidence and remediation measures.
The first cause of subsidence is aquifer system compaction, which is the compaction of unconsolidated aquifer systems accompanying excessive ground-water pumping (Galloway et al., 2009).
This is by far the major cause of land subsidence in the United States. The
Cited: October 1995). IAHS Publ. no. 234, 1995. Web. 04/01/2010. 10, pgs. 2573-2585. Oct. 1998. Web. 04/04/2010. October 20-22, 2004. Web. 04/03/2010.