Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Marine Geology”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
USGS1992

Woods Hole Image Processing System Software implementation; using NetCDF as a software interface for image processing

The Branch of Atlantic Marine Geology has been involved in the collection, processing and digital mosaicking of high, medium and low-resolution side-scan sonar data during the past 6 years. In the past, processing and digital mosaicking has been accomplished with a dedicated, shore-based computer system. With the need to process sidescan data in the field with increased power and reduced cost of major workstations, a need to have an image processing package on a UNIX based computer system which could be utilized in the field as well as be more generally available to Branch personnel was identified. This report describes the initial development of that package referred to as the Woods Hole Image Processing System (WHIPS). The software was developed using the Unidata NetCDF software interface to allow data to be more readily portable between different computer operating systems.

Open-File Report↗
USGS1992

Digital mapping of side-scan sonar data with the Woods Hole Image Processing System software

Since 1985, the Branch of Atlantic Marine Geology has been involved in collecting, processing and digitally mosaicking high and low resolution sidescan sonar data. In the past, processing and digital mosaicking has been accomplished with a dedicated, shore-based computer system. Recent development of a UNIX-based image-processing software system includes a series of task specific programs for pre-processing sidescan sonar data. To extend the capabilities of the UNIX-based programs, development of digital mapping techniques have been developed. This report describes the initial development of an automated digital mapping procedure. Included is a description of the programs and steps required to complete the digital mosaicking on a UNIXbased computer system, and a comparison of techniques that the user may wish to select.

Open-File Report↗
USGS1999

Cruise report for A1-98-SC southern California Earthquake Hazards Project

The focus of the Southern California Earthquake Hazards project, within the Western Region Coastal and Marine Geology team (WRCMG), is to identify the landslide and earthquake hazards and related ground-deformation processes that can potentially impact the social and economic well-being of the inhabitants of the Southern California coastal region, the most populated urban corridor along the U.S. Pacific margin. The primary objective is to help mitigate the earthquake hazards for the Southern California region by improving our understanding of how deformation is distributed (spatially and temporally) in the offshore with respect to the onshore region. To meet this overall objective, we are investigating the distribution, character, and relative intensity of active (i.e., primarily Holocene) deformation within the basins and along the shelf adjacent to the most highly populated areas (see Fig. 1). In addition, the project will examine the Pliocene-Pleistocene record of how this deformation has shifted in space and time. The results of this study should improve our knowledge of shifting deformation for both the long-term (105 to several 106 yr) and short-term (<50 ky) time frames and enable us to identify actively deforming structures that may constitute current significant seismic hazards.

California↗
USGS1999

Cruise report for O1-99-SC Southern California Earthquake Hazards project

The focus of the Southern California Earthquake Hazards project is to identify the landslide and earthquake hazards and related ground-deformation processes occurring in the offshore areas that have significant potential to impact the inhabitants of the Southern California coastal region. The project activity is supported through the Coastal and Marine Geology Program of the Geologic Division of the U. S. Geological Survey (USGS) and is a component of the Geologic Division's Science Strategy under Goal 1—Conduct Geologic Hazard Assessments for Mitigation Planning (Bohlen et al., 1998). The project research is specifically stated under Activity 1.1.2 of the Science Strategy: Earthquake Hazard Assessments and Loss Reduction Products in Urban Regions. This activity involves "research, seismic and geodetic monitoring, field studies, geologic mapping, and analyses needed to provide seismic hazard assessments of major urban centers in earthquake-prone regions including adjoining coastal and offshore areas." The southern California urban areas, which form the most populated urban corridor along the U.S. Pacific margin, are among a few specifically designated for special emphasis under the Division's science strategy (Bohlen et al., 1998). The primary objective of the project is to help mitigate the earthquake hazards for the Southern California region by improving our understanding of how deformation is distributed (spatially and temporally) in the offshore with respect to the onshore region. To meet this objective, we are conducting field investigations to observe the distribution, character, and relative intensity of active (i.e., primarily Holocene) deformation within the basins and along the shelf adjacent to the most highly populated areas (Fig. 1). In addition, acoustic imaging should help determine the subsurface dimensions of the faults and identify the size and frequency of submarine landslides, both of which are necessary for evaluating the potential for generating destructive tsunamis in the southern California offshore. In order to evaluate the strain associated with the offshore structures, the initial results from the field mapping under this project will be used to identify possible sites for deployment of acoustic geodetic instruments to monitor strain in the offshore region. A major goal of mapping under this project is to provide detailed geologic and geophysical information in GIS data bases that build on the earlier studies and use the new data to precisely locate active faults and to map recent submarine landslide deposits.

California↗
USGS1995

Seafloor environments within the Boston Harbor-Massachusetts Bay sedimentary system: a regional synthesis

Modern seafloor sedimentary environments within the glaciated, topographically complex Boston Harbor and Massachusetts Bay area have been interpreted and mapped from an extensive collection of sidescan sonar records and supplemental marine geologic data. Three categories of environments are present that reflect the dominant long-term processes of erosion or nondeposition, deposition, and sediment reworking. Indicates areas within the Boston Harbor-Massachusetts Bay sedimentary system where fine-grained sediments and associated contaminants are likely to be either moved or deposited. It also provides a guide to the locations and variability of benthic habitats. -from Authors

Journal of Coastal Research↗
USGS2000

Sea-floor environments within Long Island Sound: A regional overview

Modern sea-floor sedimentary environments within the glaciated, topographically complex Long Island Sound estuary have been interpreted and mapped from an extensive collection of sidescan sonographs, bottom samples, and video-camera observations together with supplemental bathymetric, marine-geologic, and bottom-current data. Four categories of environments are present that reflect the dominant long-term processes of erosion or nondeposition; coarsegrained bedload transport; sediment sorting and reworking; and fine-grained deposition. (1) Environments of erosion or nondeposition contain exposures of glacial drift, coarse lag deposits, and possibly bedrock and include sediments which range from boulder fields to gravelly coarse-to-medium sands. (2) Environments of coarse-grained bedload transport are mantled by sand ribbons and sand waves and contain mostly coarse-to-fine sands with only small amounts of mud. (3) Environments of sediment sorting and reworking comprise both uniform and heterogeneous sediment types and contain variable amounts of fine sand and mud. (4) Environments of fine-grained deposition are blanketed by muds and sandy muds. The patchy distribution of sedimentary environments within Long Island Sound reflects both regional and local changes in bottom processes. Regional changes are primarily the result of a strong, east-to-west decreasing gradient of bottom tidal-current speeds, coupled with the net (westward) estuarine bottom drift. The regional current regime has produced a westward succession of environments along the basin floor beginning with erosion or nondeposition at the narrow eastern entrance to the Sound, changing to an extensive area of coarse-grained bedload transport, passing into a contiguous band of sediment sorting, and ending with broad areas of fine-grained deposition in the central and western Sound. However, local changes in processes are superimposed on the regional conditions within the central and western parts of the basin and along the nearshore margins. Within the central and western basin, localized sedimentary environments are produced where the bottom flow is enhanced by, and interacts with, the bottom topography, whereas along the nearshore margins, they variously reflect wave-produced currents, the irregular bathymetry, the indented shoreline, and the proximal supply of sediments. Results from this study (1) confirm the high trapping efficiency of fine-grained sediments in the Sound, (2) suggest that fine-grained sediments accumulate at an average (regional) rate of 0.08 g/cm 2 /y , and (3) indicate that the postglacial delta in the eastern Sound was a significant source of fine-grained sediments now buried beneath depositional areas.

Connecticut, New York↗
USGS1995

Seafloor environments within the Boston Harbor- Massachusetts Bay sedimentary system: A regional synthesis

Modern seafloor sedimentary environments within the glaciated, topographically complex Boston Harbor and Massachusetts Bay area have been interpreted and mapped from an extensive collection of sidescan sonar records and supplemental marine geologic data. Three categories of environments are present that reflect the dominant long-term processes of erosion or nondeposition, deposition, and sediment reworking. (1) Environments of erosion or nondeposition comprise exposures of bedrock, glacial drift, coarse lag deposits, and possibly coastal plain rocks that contain sediments (where present) ranging from boulder fields to gravelly sands and occur in areas of relatively strong currents. (2) Environments of deposition contain fine-grained sediments ranging from muddy sands to muds that have accumulated in areas of predominantly weak bottom currents. (3) Environments of sediment reworking contain patches with textures ranging from sandy gravels to muds that have been produced by a combination of erosion and deposition in areas with variable bottom currents. The distribution of sedimentary environments across the Boston Harbor-Massachusetts Bay area is extremely patchy. Locally, this patchiness is due either to modifications of bottom-current strength (caused by the irregular topography and differences in water depth) or to small-scale changes in the supply of fine-grained sediments. Regional patchiness, however, reflects differences in geologic and oceanographic conditions among the estuarine, inner shelf, and basinal parts of the sedimentary system. The estuarine part of the system (Boston Harbor) is a depositional trap for fine-grained sediments because it is protected from large waves, has generally weak and variable tidal currents, and receives a large supply of fine grained detritus from natural and anthropogenic sources. The inner shelf, on the other hand, is largely an area of erosion or nondeposition due to sediment removal and redistribution during past sea-level changes, to sediment resuspension and winnowing by modern waves and currents, and to an inadequate supply of fine-grained sediments. The basinal part of the system (Stellwagen Basin) is mainly a tranquil depositional environment in which fine-grained sediments from several potential sources settle through the water column and accumulate under weak bottom currents. This study indicates areas within the Boston Harbor-Massachusetts Bay sedimentary system where fine-grained sediments and associated contaminants are likely to be either moved or deposited. It also provides a guide to the locations and variability of benthic habitats.

Massachusetts Bay↗
USGS1972

Preliminary mariner 9 report on the geology of Mars

Mariner 9 pictures indicate that the surface of Mars has been shaped by impact, volcanic, tectonic, erosional and depositional activity. The moonlike cratered terrain, identified as the dominant surface unit from the Mariner 6 and 7 flyby data, has proven to be less typical of Mars than previously believed, although extensive in the mid- and high-latitude regions of the southern hemisphere. Martian craters are highly modified but their size-frequency distribution and morphology suggest that most were formed by impact. Circular basins encompassed by rugged terrain and filled with smooth plains material are recognized. These structures, like the craters, are more modified than corresponding features on the Moon and they exercise a less dominant influence on the regional geology. Smooth plains with few visible craters fill the large basins and the floors of larger craters; they also occupy large parts of the northern hemisphere where the plains lap against higher landforms. The middle northern latitudes of Mars from 90 to 150† longitude contain at least four large shield volcanoes each of which is about twice as massive as the largest on Earth. Steep-sided domes with summit craters and large, fresh-appearing volcanic craters with smooth rims are also present in this region. Multiple flow structures, ridges with lobate flanks, chain craters, and sinuous rilles occur in all regions, suggesting widespread volcanism. Evidence for tectonic activity postdating formation of the cratered terrain and some of the plains units is abundant in the equatorial area from 0 to 120° longitude.Some regions exhibit a complex semiradial array of graben that suggest doming and stretching of the surface. Others contain intensity faulted terrain with broader, deeper graben separated by a complex mosaic of flat-topped blocks. An east-west-trending canyon system about 100–200 km wide and about 2500 km long extends through the Coprates-Eos region. The canyons have gullied walls indicative of extensive headward erosion since their initial formation. Regionally depressed areas called chaotic terrain consist of intricately broken and jumbled blocks and appear to result from breaking up and slumping of older geologic units. Compressional features have not been identified in any of the pictures analyzed to data. Plumose light and dark surface markings can be explained by eolian transport. Mariner 9 has thus revealed that Mars is a complex planet with its own distinctive geologic history and that it is less primitive than the Moon.

Icarus↗
USGS1984

U. S. GEOLOGICAL SURVEY MARINE-MINERALS RESEARCH.

Summary form only given. The US Exclusive Economic Zone is an area approximately one and two-thirds the size of the land area of the United States. In this frontier area, US Geological Survey (USGS) research in marine minerals is aimed at three objectives: (1) defining geologic settings of potential mineral resources; (2) understanding the processes by which seafloor nonliving resources form; and (3) estimating the resource potential. Potential resources of primary interest are cobalt-rich manganese seafloor crusts, polymetallic sulfides in hydrothermal vent areas on the seafloor, and heavy-mineral placer deposits. Research activities include studies of manganese-crust samples from oceanographic-institution archives and a USGS research cruise through the central and southern Pacific. Preliminary results confirm that cobalt is concentrated by as much as 2. 5% in the manganese crusts at water depths of 1000-2600 m; further research on the precipitation processes and patterns of crust formation will be needed to understand the origin, occurrence patterns, and resource potential of these crusts. Research cruises have revealed a zone of polymetallic sulfide vent deposits a few hundred meters long in the Juan de Fuca spreading center.

Conference Paper↗
USGS2019

Coastal and marine science of the U.S. Geological Survey in Woods Hole, Massachusetts

The U.S. Geological Survey (USGS) Woods Hole Coastal and Marine Science Center in Woods Hole, Massachusetts, is one of three centers serving the mission of the USGS Coastal and Marine Hazards and Resources Program (CMHRP). Since its authorization by Congress in 1962, the CMHRP has served as the primary Federal program for marine geology and physical science research and is responsible for the Nation’s entire coastal and marine landscape. The center’s staff of about 100 conducts scientific research in various locations throughout the United States to describe and understand the processes shaping coastal ecosystems, such as dunes, beaches, salt marshes, and lakes, and marine ecosystems, like the continental shelf and the deep sea. The center’s research products are used by other Federal agencies, State and local entities, private organizations, and the public to make informed decisions about the use, management, and protection of our coastal and marine resources.

Massachsetts↗
USGS2021

Coastal and marine science of the U.S. Geological Survey in St. Petersburg, Florida

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) in St. Petersburg, Florida, investigates processes that form and alter coastal and marine environments and the implications of these processes related to natural hazards, resource sustainability, and environmental change. The center is one of three facilities serving the mission of the USGS Coastal and Marine Hazards and Resources Program, an initiative authorized by Congress in 1962 that serves as the primary Federal program for marine geology and physical science research and is responsible for the Nation’s entire coastal and marine landscape. The center’s staff conducts scientific research around the globe to describe and deepen understanding of the processes that influence coastal and marine ecosystems, such as sandy beaches and barrier islands, salt marshes and estuaries, coral reefs, and the open ocean from the continental shelf to the deep sea. The center includes a diverse workforce of scientists, technicians, administrators, analysts, and technology and information specialists. This team works collaboratively to conduct and share robust scientific research. This document provides a glimpse into the center’s work to better understand the processes shaping coastal and marine environments across the Nation.

Florida↗
USGS2002

Nearshore morphology and late Quaternary geologic framework of the northern Monterey Bay Marine Sanctuary, California

A combination of side-scanning sonar and high-resolution seismic reflection data image seafloor bedrock exposures and erosional features across the nearshore shelf. Sediment-filled troughs incise the inner shelf rock exposures and tie directly to modern coastal streams. The resulting bedrock geometry can be related to its resistance to erosion. Comparison of the depth of the transgressive erosional surface to recently developed sea level curves suggests a period of slow sea level rise during the early stages of post-interglacial marine transgression. The slow rise of sea level suggests an erosional episode that limited the preservation of buried paleo-channels beyond 70 m water depth. Seafloor features suggest that localized faulting in the area may have influenced the morphology of bedrock exposures and the coastline. ?? 2002 Elsevier Science B.V. All rights reserved.

Marine Geology↗
USGS2023

Pacific coastal and marine science of the U.S. Geological Survey in Santa Cruz, California

Introduction The Pacific Coastal and Marine Science Center is one of three U.S. Geological Survey science centers that serve the mission of the Coastal and Marine Hazards and Resources Program, the primary Federal marine geology and physical science research program focused on the Nation’s coastal and marine landscape. Our portfolio of coastal and marine projects in the Pacific Ocean provides the scientific information necessary to sustainably manage coastal and marine resources, to prepare for natural hazard events such as landslides and tsunamis, and to build resilience in coastal communities vulnerable to the effects of climate change, as well as storms, flooding, and risks to groundwater resources. The Nation’s demand for societally relevant coastal and marine science has never been greater, and we invite you to explore some of our ongoing Pacific Coastal and Marine Science Center activities in these pages.

General Information Product↗
USGS1993

Geologic assessments and characterization of marine sand resources - Gulf of Mexico region

The U.S. Geological Survey conducts geologic surveys and research in marine areas of the United States and its territories and possessions. An objective in some of the investigations is locating and evaluating marine sand and gravel resources and interpretation of the origins of the sand body deposits. Results from such studies over the past 30 years show that many extremely large deposits are located close to expanding metropolitan areas, which have a need for aggregate materials for construction, and near-developed coastal areas, where beach replenishment may be used to mitigate coastal erosion. The Gulf of Mexico continental shelf from the Florida Peninsula to the Mexico border is an enormous area, but little attention has been directed on sand and gravel resources. Based on limited surveys, the total sand and gravel resources for the entire Gulf of Mexico is estimated to be 269 billion cubic meters. However, the sand tends to be fine-grained and is often mixed with mud; gravel deposits, except for shell, are mostly nonexistent.

Conference Paper↗
USGS2015

Collections management plan for the U.S. Geological Survey Woods Hole Coastal and Marine Science Center Data Library

The U.S. Geological Survey Woods Hole Coastal and Marine Science Center has created a Data Library to organize, preserve, and make available the field, laboratory, and modeling data collected and processed by Woods Hole Coastal and Marine Science Center staff. This Data Library supports current research efforts by providing unique, historic datasets with accompanying metadata. The Woods Hole Coastal and Marine Science Center&rsquo;s Data Library has custody of historic data and records that are still useful for research, and assists with preservation and distribution of marine science records and data in the course of scientific investigation and experimentation by researchers and staff at the science center. The data accession and retention policies employed by the Woods Hole Coastal and Marine Science Center Data Library are based on scientific need and the National Archives and Records Administration standards for Federal records retention. Criteria for inclusion of data and records into the Data Library, the scope of the Data Library holdings, and operating procedures for the management and running of the library are designed to support the research operations of the U.S. Geological Survey. This report explains the roles and detailed responsibilities of library and scientific staff, and provides step-by-step instructions for managing the collections of the Woods Hole Coastal and Marine Science Center Data Library.

Open-File Report↗