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Mark Hansen

Publications and source records attributed to Mark Hansen.

15 recordsLinked to original sources
USGS2012

Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama

Breaching of barrier islands can adversely impact society by severing infrastructure, destroying private properties, and altering water quality in back bays and estuaries. This study provides a scheme that assesses the relative vulnerability of a barrier island to breach during storms. Dauphin Island, Alabama was selected for this study because it has a well documented history of island breaches and extensive geological and geomorphic data. To assess the vulnerability of the island, we defined several variables contributing to the risk of breaching: island geology, breaching history, and island topography and geomorphology. These variables were combined to form a breaching index (BI) value for cross island computational bins, each bin every 50 m in the alongshore direction. Results suggest the eastern section of Dauphin Island has the lowest risk of breaching with the remaining portion of the island having a moderate to high risk of breaching. Two reaches in the western section of the island were found to be particularly vulnerable due primarily to their minimal cross-sectional dimensions.

Alabama↗
USGS2012

Archive of single-beam bathymetry data collected during USGS cruise 07CCT01 nearshore of Fort Massachusetts and within Camille Cut, West and East Ship Islands, Gulf Islands National Seashore, Mississippi, July 2007

The Gulf Islands National Seashore (GUIS) is composed of a series of barrier islands along the Mississippi - Alabama coastline. Historically these islands have undergone long-term shoreline change. The devastation of Hurricane Katrina in 2005 prompted questions about the stability of the barrier islands and their potential response to future storm impacts. Additionally, there was concern from the National Park Service (NPS) about the preservation of the historical Fort Massachusetts, located on West Ship Island. During the early 1900s, Ship Island was an individual island. In 1969 Hurricane Camille breached Ship Island, widening the cut and splitting it into what is now known as West Ship Island and East Ship Island. In July of 2007, the U.S. Geological Survey (USGS) was able to provide the NPS with a small bathymetric survey of Camille Cut using high-resolution single-beam bathymetry. This provided GUIS with a post-Katrina assessment of the bathymetry in Camille Cut and along the northern shoreline directly in front of Fort Massachusetts. Ultimately, this survey became an initial bathymetry dataset toward a larger USGS effort included in the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility Project ( http://ngom.usgs.gov/gomsc/mscip/ ). This report serves as an archive of the processed single-beam bathymetry. Data products herein include gridded and interpolated digital depth surfaces and x,y,z data products. Additional files include trackline maps, navigation files, geographic information system (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Scanned images of the handwritten FACS logs and digital FACS logs are also provided as PDF files. Refer to the Acronyms page for description of acronyms and abbreviations used in this report or hold the cursor over an acronym for a pop-up explanation. The USGS St. Petersburg Coastal and Marine Science Center assigns a unique identifier to each cruise or field activity. For example, 07CCT01 tells us the data were collected in 2007 for the Coastal Change and Transport (CCT) study and the data were collected during the first (01) field activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity ID. Data were collected using a 26-foot (ft) Glacier Bay catamaran. The single-beam transducers were sled mounted on a rail attached between the catamaran hulls. Navigation was acquired using HYPACK, Inc., Hypack version 4.3a.7.1 and differentially corrected using land-based GPS stations. See the digital FACS equipment log for details about the acquisition equipment used. Raw datasets were stored digitally and processed systematically using NovAtel's Waypoint GrafNav version 7.6, SANDS version 3.7, and ESRI ArcGIS version 9.3.1. For more information on processing refer to the Equipment and Processing page.

Mississippi↗
USGS2010

Cartographic Production for the FLaSH Map Study: Generation of Rugosity Grids, 2008

Project Summary This series of raster data is a U.S. Geological Survey (USGS) Data Series release from the Florida Shelf Habitat Project (FLaSH). This disc contains two raster images in Environmental Systems Research Institute, Inc. (ESRI) raster grid format, jpeg image format, and Geo-referenced Tagged Image File Format (GeoTIFF). Data is also provided in non-image ASCII format. Rugosity grids at two resolutions (250 m and 1000 m) were generated for West Florida shelf waters to 250 m using a custom algorithm that follows the methods of Valentine and others (2004). The Methods portion of this document describes the specific steps used to generate the raster images. Rugosity, also referred to as roughness, ruggedness, or the surface-area ratio (Riley and others, 1999; Wilson and others, 2007), is a visual and quantitative measurement of terrain complexity, a common variable in ecological habitat studies. The rugosity of an area can affect biota by influencing habitat, providing shelter from elements, determining the quantity and type of living space, influencing the type and quantity of flora, affecting predator-prey relationships by providing cover and concealment, and, as an expression of vertical relief, can influence local environmental conditions such as temperature and moisture. In the marine environment rugosity can furthermore influence current flow rate and direction, increase the residence time of water in an area through eddying and current deflection, influence local water conditions such as chemistry, turbidity, and temperature, and influence the rate and nature of sedimentary deposition. State-of-the-art computer-mapping techniques and data-processing tools were used to develop shelf-wide raster and vector data layers. Florida Shelf Habitat (FLaSH) Mapping Project (http://coastal.er.usgs.gov/flash) endeavors to locate available data, identify data gaps, synthesize existing information, and expand our understanding of geologic processes in our dynamic coastal and marine systems.

Data Series↗
USGS2007

Estimation of post-Katrina debris volume

Hurricane Katrina severely impacted coastal Mississippi, creating large quantities of building and vegetation debris. This paper summarizes techniques to estimate vegetation and nonvegetation debris quantities from light detection and ranging (lidar) data and presents debris volume results for Harrison County, Miss.

Mississippi↗
USGS2007

Bathymetric survey of the nearshore from Belle Pass to Caminada Pass, Louisiana: Methods and data report

The U.S. Geological Survey (USGS), in cooperation with the University of New Orleans (UNO) and the Louisiana Department of Natural Resources (LDNR), conducted a high-resolution, single-beam bathymetric survey along the Louisiana southern coastal zone from Belle Pass to Caminada Pass. The survey consisted of 483 line kilometers of data acquired in July and August of 2005. This report outlines the methodology and provides the data from the survey. Analysis of the data and comparison to a similar bathymetric survey completed in 1989 show significant loss of seafloor and shoreline retreat, which is consistent with previously published estimates of shoreline change in the study area.

Louisiana↗
USGS2007

Cartographic production for the Florida Shelf Habitat (FLaSH) map study: generation of surface grids, contours, and KMZ files

The Florida shelf represents a finite source of economic resources, including commercial and recreational fisheries, tourism, recreation, sand and gravel resources, phosphate, and freshwater reserves. Yet the basic information needed to locate resources, or to interpret and utilize existing data, comes from many sources, dates, and formats. A multi-agency effort is underway to coordinate and prioritize the compilation of suitable datasets for an integrated information system of Florida’s coastal and ocean resources. This report and the associated data files represent part of the effort to make data accessible and useable with computer-mapping systems, web-based technologies, and user-friendly visualization tools. Among the datasets compiled and developed are seafloor imagery, marine sediment data, and existing bathymetric data. A U.S. Geological Survey-sponsored workshop in January 2007 resulted in the establishment of mapping priorities for the state. Bathymetry was identified as a common priority among agencies and researchers. State-of-the-art computer-mapping techniques and data-processing tools were used to develop shelf-wide raster and vector data layers. Florida Shelf Habitat (FLaSH) Mapping Project ( http://coastal.er.usgs.gov/flash ) endeavors to locate available data, identify data gaps, synthesize existing information, and expand our understanding of geologic processes in our dynamic coastal and marine systems.

Florida↗
USGS2006

Hurricanes 2004: An overview of their characteristics and coastal change

Four hurricanes battered the state of Florida during 2004, the most affecting any state since Texas endured four in 1884. Each of the storms changed the coast differently. Average shoreline change within the right front quadrant of hurricane force winds varied from 1 m of shoreline advance to 20 m of retreat, whereas average sand volume change varied from 11 to 66 m 3 m −1 of net loss (erosion). These changes did not scale simply with hurricane intensity as described by the Saffir-Simpson Hurricane Scale. The strongest storm of the season, category 4 Hurricane Charley, had the least shoreline retreat. This was likely because of other factors like the storm's rapid forward speed and small size that generated a lower storm surge than expected. Two of the storms, Hurricanes Frances and Jeanne, affected nearly the same area on the Florida east coast just 3 wk apart. The first storm, Frances, although weaker than the second, caused greater shoreline retreat and sand volume erosion. As a consequence, Hurricane Frances may have stripped away protective beach and exposed dunes to direct wave attack during Jeanne, although there was significant dune erosion during both storms. The maximum shoreline change for all four hurricanes occurred during Ivan on the coasts of eastern Alabama and the Florida Panhandle. The net volume change across a barrier island within the Ivan impact zone approached zero because of massive overwash that approximately balanced erosion of the beach. These data from the 2004 hurricane season will prove useful in developing new ways to scale and predict coastal-change effects during hurricanes.

Alabama, Florida, Georgia, Louisiana, Mississippi,↗
USGS2005

Gulf of Mexico Integrated Science - Tampa Bay Study: Watershed and Estuary Mapping

Tampa Bay, Florida, and its environs have experienced phenomenal urban growth and significant changes in land-use practices over the past 50 years. This trend is expected to continue, with human activity intensifying and affecting a wider geographic region. Urbanization creates impervious surfaces, which increase stormwater runoff and contribute to greater amounts of chemicals flowing into coastal waters. Man-made structures including bridges, a gas pipeline, desalination plant, ports, navigation channels, and extensive sea walls have been built and will continue to be maintained and modified. This task of the Tampa Bay Study aims to provide a better understanding of these and other man-made impacts on the Tampa Bay region.

Open-File Report↗
USGS2002

Initial results from a test of the NASA EAARL lidar in the Tampa Bay region

An initial test of the performance of the NASA Experimental Advanced Airborne Research Lidar ( EAARL ) over coastal environments around the margins of an urbanized Gulf of Mexico estuary was performed over Tampa Bay in January 2002 . The EAARL is a raster-scanning, water-penetrating, full-waveform adaptive lidar that is coupled to aircraft positioning systems and a downlooking color digital camera. The EAARL has unique capabilities for simultaneously mapping topography, shallow bathymetry, and vegetation. Initial analysis within 2 Tampa Bay subregions traversed by the survey flightlines has revealed that the EAARL can survey shallow bathymetry and variables associated with benthic cover in remarkable detail. The results of this ongoing study will aid in developing recommendations on the appropriate use of NASA EAARL surveys for mapping bathymetry and benthic habitats in estuaries around the Gulf of Mexico.

Florida↗
USGS2000

1890 and 1990 Bathymetry of Florida Bay

This Open File Report contains bathymetric data collected in Florida Bay by the US Geological Survey, South Florida Place-Based Studies Program using SANDS (System for Accurate Nearshore Depth Surveying). SANDS is a USGS developed, high precision bathymetric system which integrates depth soundings, boat motion, and GPS positioning needed for nearshore bathymetric mapping. Data acquisition occurred between 1995 and 1999 on a 22' shallow draft boat. Processed data points are in X, Y, Z format and relative to the North American Datum of 1983 (GRS80/NAD83) and the North American Vertical Datum of 1988 (NAVD88). Vertical control was derived from GPS data processed with Jet Propulsion Laboratory GIPSY software. Horizontal and vertical accuracies are within +/- 4 centimeters and +/- 8 centimeters, respectively.

Florida↗