Science for Decisionmaking Coastal and Marine Geology at the U.S. Geological Survey (1999) / Chapter Skim
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3 Future Program Emphasis
3 Future Program Emphasis
Pages 40-50
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From page 40... ...
Rising sea level and rapid subsidence, along with human activities, are destroying one of the largest wetland regions along the northern Gulf of Mexico. In southern Florida and along the tropical islands of the Pacific and Caribbean, the abundantly diverse and rich coral reefs are degrading at an increasing rate.
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From page 41... ...
Although the committee understands that the variability and complexity of the continental margins is a familiar concept to geoscientists in general, the following discussion is included here to help establish a framework for discussing CMGP's grand challenges and near-term focus areas. It is from this perspective that the committee then argues the value of the grand challenges that face the nation's coastal and marine regions.
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From page 42... ...
This variability is perhaps most easily seen by comparing the geologic structure of the areas making up the continental margins of the United States, which can be categorized into eight major provinces: Province 1 The Pacific Northwest A volcanically and tectonically active province that includes a spreading center and a subductive compressive margin. The province is characterized by: · volcanic and earthquake processes and massive active margin faulting; · extensive hydrothermal activity along the spreading center, resulting in the formation of metal-rich sulfide deposits and chemosynthesis-based biological communities; · areas of simultaneous rapid uplift and subsidence; · a glacially shaped margin with a major river depositing large quantities of sediment that builds the edge of continental margin; and · strong littoral currents, high persistent wave energy, and periodic tsunamis.
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From page 43... ...
Province 3 Western and Central Gulf Coast A river-dominated coastal system characterized by: · a large persistent influx of river-borne sediments and freshwater and related density contrasts; high sediment loading, which causes rapid subsidence and diapiric salt . intrusions; · a low wave and tidal energy coastal zone that is periodically inundated by intense hurricanes; · a broad, gentle continental shelf with complex localized salt withdrawal basins; .
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From page 44... ...
Province 5 East Coast A passive continental margin characterized by: an ancient rift margin; a mesotidal system with strong, persistent littoral currents; extensive, persistent beach-barrier estuary complexes; strong winter storms and passages of intense hurricanes a continuous coastal sand stream; and · a northeastern section dominated by remnants of Quaternary glaciation and coastal rebound. The east coast province in the south overlaps with the Florida platform at the wide Blake Plateau.
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From page 45... ...
ur nation's most diverse coastal and marine province is characterized by: · a southern margin with extreme vertical tectonics, no large rivers, and strong long-shore drift; an ice-scoured northern margin that is an ancient passive margin with drastic seasonal variations in depositional environment; and a western margin dominated by arc-related and strike-slip Tertiary basins that receive huge seasonal influxes of sediment; . the highest rates of North American vertical tectonics of the Alaskan hinterland arc; · wetlands that are greatly different from the other provinces because of their dominance by seasonal permafrost and arctic processes; and · the most diverse and intense natural hazards in the country.
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From page 46... ...
Province 8 Tropical Island Province Volcanic islands characterized by: · highly variable tectonic and volcanic activity in which the dominant sedimentary deposits are biogenic or volcanogenic; · variable but narrow continental margins cut by numerous submarine canyons bordered by adjacent deep-sea trenches; · diverse tectonic uplift and subsidence patterns; · high wave energy and episodic storm events; and · variable hazards, including volcanic activity, coastal and submarine landslides, and tsunamis. The tropical islands cover extremely variable provinces from the volcanic island chain of the Hawaiian Islands and other Pacific islands to the Caribbean.
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From page 47... ...
A national assessment has to be based on sound fundamental, integrated science (which has been a characteristic of CMPG) but with a broad perspective framed by an understanding of the different geologic settings of the eight provinces of the continental margins.
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From page 48... ...
Grand Challenge 2: Develop a National Knowledge Bank on the Geologic Framework of the Country's Coastal and Marine Regions This coastal and marine geological knowledge bank should serve as a comprehensive inventory of geologic data developed by all interested agencies, academic institutions, and state agencies much like the knowledge bank of U.S. oil and gas resources, which has been developed by the USGS energy resource program and the Minerals Management Service.
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From page 49... ...
This data gathering leads to or facilitates: · systematic organization of data and information, · development of pertinent questions about the geologic framework of the province and its active processes, ing, and · selection and prioritization of projects for developing data that are lack · communication with other federal and state agencies and state geological surveys leading to cooperative ventures. Finally, development of a method to derive custom products on demand will likely raise questions regarding competition with the private sector there are some existing businesses that function as resellers of USGS data, sometimes reprocessed for specific purposes, sometimes not.
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From page 50... ...
The CMGP should expand and strengthen quantitative model development and change-forecast products to meet management needs for defining the future geologic framework of coastal margins. This approach is consistent with the pursuit of other grand challenges and with the scientific methods and the principles of adaptive management.
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