Marine Geology Investigations

Authorization: 43 U.S.C. 31(a)

Objectives: The program goals are (a) testing advanced geologic research concepts applicable to the marine environment and resources, and (b) data synthesis for the Survey's programs, for other Federal agencies and for government entities of coastal States. Investigations on the geologic conditions, processes and non-energy mineral resources are conducted, in coastal and estuarine areas, in lakes, on the continental shelf and slope and in deep ocean areas in support of other missions of the Geological Survey.

Base Program:

Investigations are conducted to determine the source and process of mineral enrichment of deep-sea sediments, overlying the oceanic crust, that could contain economically valuable minerals such as manganese, nickel, and cobalt. Research on marine sediments, which include sand and gravel, heavy minerals, manganese nodules and other critical mineral commodities, is being conducted on the continental shelf off New England, California, and Alaska and selected deep water areas by means of geochemical, hydrochemical, geophysical and sampling techniques. FY 1982, these studies will be continued.

In

Investigations in the coastal zone of Texas, Massachusetts and Puerto Rico are conducted in cooperation with State Government agencies. Seismic and magnetic measurements in lakes, including the Great Lakes, are part of the coastal zone research efforts.

Instruments for monitoring earthquake activities, transport of coastal sediments and the related ocean waves and currents are being developed, tested, and deployed in coastal and continental shelf areas.

Areas and topics under investigations in FY 1982 include:

O Study trace metals in sediments, and continued evaluation of manganese nodules and phosphorites by geochemical, geophysical and other methods.

Process and interpret wide-swath sonar records of the Atlantic continental slope to delineate morphological provinces and determine unstable seafloor areas.

о Continue evaluations on the structure, stratigraphy and geologic hazards of lakes.

O Continue cooperative studies with coastal States to provide maps and reports to coastal States and Government agencies.

Major accomplishments of this program have been:

o Development of instrumentation for investigations on offshore seismicity and coastal erosion.

Participation in multi-national investigations of hydrothermal vents associated with large deposits of copper, zinc, and iron sulfides.

Identification of marine sand deposits offshore of Puerto Rico for purposes of commercial extraction, and determination of geologic conditions around pipeline corridors.

Marine geologic maps have been completed for the shelf off Puerto Rico and Massachusetts.

Study of manganese nodules on the Atlantic Margin has shown high concentrations of platinum.

The seaward extent of phosphorite deposits off Florida were delineated.

Objectives: The principal objectives of this program are (a) to improve the understanding of geologic processes of engineering significance in frontier (Continental Slope and Rise, and Arctic Outer Continental Shelf) areas, (b) to devise and use improved techniques for evaluating physical and engineering properties of earth materials in the marine environment, and for predicting the behavior of these materials under changing physical conditions, and (c) to provide marine geologic engineering information and expertise to areas where a major Federal interest exists.

An increase of $1,948,000 is requested to initiate a program, principally in seafloor engineering for the deep-water (Continental Slope) and Arctic OCS areas. Unique problems in these areas require specific. environmental and geotechnical engineering solutions. The Survey has conducted pilot studies in shallow waters (Continental Shelf) already, whose accomplishments are listed in the base program statement, hence has a partial capability to address issues of this proposed activity. The increase is requested to allow the Survey to formally establish this program and expand its capabilities to the new areas of concern.

Figure G-13 shows the promising deep water areas of the Gulf of Mexico where studies that will be addressed in the program are critical to the development of oil and gas resources.

The program is specifically tailored to special problems of deep-water and Arctic OCS development, principally for oil and gas. The most recent estimates indicate that a significant portion of the Nation's remaining undiscovered recoverable oil and gas resources lies in deep water areas and in Arctic basins, and the present leasing schedule reflects this. The program is, however, applicable to future leasing and development of other commodities, such as hard minerals. Information gathered in this program is for the specific purpose of quantifying environmental and geologic conditions in engineering terms to advance knowledge of hazards from unsatisfactory to acceptable, and in this manner assist in accelerating leasing and development of offshore Federal lands. The program is specifically aimed at unique problems of the deep water areas (Continental Slope and Rise) and the Arctic OCS, where the nature and behavior of earth materials and related environmental settings are incompletely understood at present. The impact anticipated is that leasing could proceed in a timely and litigation-free manner, that industry obtain guidance from results of this program for improving design parameters for offshore construction and operations, and that other Federal agencies, State agencies, and the concerned public will be able to use the information to assist advancing the development of mineral resources of the OCS and deep oceans.

The program is focused on (a) regional assessment of the engineering characteristics of materials on and below the seafloor, (b) the development of quantitative understanding and assessments of the mechanics of geotechnical, seismic and selected oceanographic processes in the marine environment, and (c) closing critical gaps in geotechnology relating to the behavior, and on disturbance, effects of marine soils by means of new engineering measurement techniques, and (d) development of experimental and analytical modeling techniques for predicting causes and effects. Among the critical issues to be addressed by this program are gas-charged unstable

Figure 0-11

eafloor soils, instabilities resulting from loading of soils by earthquakes nd ocean waves, potential failures and modes of failure of submarine andslides, slumps and creeps, and effects of potentially unstable steep lopes in deep water on siting and structural design of oil and gas latforms, the relation between ice gouges and pipeline route options in the Arctic, the engineering properites of ice-bonded sediments (permafrost and as hydrates) on drilling, casing, production technologies and on evaluating ptions for foundation design, and ground failure mechanisms resulting from arthquakes in the offshore environment. The concerns attached to eveloping these resources is that technology to produce these resources may ot yet be available, especially for areas such as the Chukchi Sea and for ater depths greater than 2000 meters because of the unique engineering roblems that must be solved prior to development. This program, therefore, s specifically designed to accelerate knowledge of the critical problems dentified for these areas, with the aim that the time lag between leasing nd development could hence be reduced. Program priorities will be based argely on the Department of the Interior's lease-sale schedules and on ndustry's plans for development of leased areas. Program emphasis will be e-evaluated annually.

nalysis of the geologic engineering conditions in these lease areas will be rovided to the pre-sale environmental impact evaluations of BLM, to the onservation Division of the Geological Survey for its regulatory responsiilities in post-sale development, and to other Federal agencies and State gencies having interest in the development of the OCS.

n FY 1982, the program will initiate studies of regional geotechnical ssessments in three OCS areas, with emphasis on the Mid-Atlantic and North tlantic deep-water OCS areas, and in one of the Bering Sea OCS areas. imultaneously, instruments developed in prior years will be used in a major tudy of the effects of pore pressure on the stability of seafloor soils. ʼn subsequent years, other deepwater lease areas, such as in the Gulf of exico, and other Arctic OCS areas such as Beaufort and Chukchi Seas will be mvestigated.

Ithough this program is to begin in FY 1982, pilot engineering studies have een conducted on the Continental Shelf in FY 1980-1981, whose significant complishments, useful to this program, were:

o Development of instrumentation for and measurement of strong-motion earthquakes in the OCS, in cooperation with the Department of Energy and industry;

o Determining that storm (hurricane) waves increase the pore pressures in soft sediments in the Gulf of Mexico, which could initiate rapid movement of large masses of sediments;

o Development of instrumentation that allows the determination of the effect of gas on the stability of the seafloor soils;

o Application of wave-hindcast models to the Atlantic OCS, on contract with NOAA, which will be used to evaluate how wave loads affect the seafloor soils, structures and their foundations;