U.S. Geological Survey Open-File Report 02-002
Geological Framework Data from Long Island Sound, 1981-1990:
A Digital Data Release
Block Island Sound: AST81-2 Seismic Profiles
The seismic profiles generated during leg 2 of the 1981 the RV ASTERIAS cruise to Block Island Sound and easternmost Long Island Sound can be accessed through either a trackline map or through a tabular data listing.
To access the seismic-reflection profiles through the trackline map, click on the line number to bring up a down-sampled grey-scale 'GIF' image of that seismic line. The seismic line preview will be displayed in a new browser window. Some seismic lines were completed in two or more segments. When selecting one of those lines, all the line segment images will be displayed in a single html page. The seismic images may also be found by browsing the data/seismics/81_2seis directory located at the top level of this report.
To view the seismic-reflection profiles through the data listing contained in the table below, click on the name of the PREVIEW IMAGE to display a down-sampled 'GIF' image of that seismic line. The image will be displayed in a new browser window. All PREVIEW IMAGE's have been reduced to 72dpi and a maximum width of 1000 pixels for optimum viewing with a web browser. Because the preview images have been reduced to a standard length of 1000 pixels, please note that the images will not be of the same scale. To access a full-resolution image of the seismic profile, the user is advised to download the desired 'TIF' image, exit their browser, and open the file in an appropriate graphics application (such as Corel Draw 12 or Adobe Photoshop CS2). Instructions for downloading the full-resolution images follow the data listing.
The file naming structure for the seismic-reflection files is based on a cruise identifier, the line number, and a character indicating the section of that line (in case a line had to be broken into several sections). For example, a81_212b.tif signifies the RV ASTERIAS as the vessel, 1981 as the year, 2 as the leg, 12 as the line number, and b as the section. The sections are listed chronologically in alphabetical order and are not necessarily geographically continuous. The suffix indicates file format.
To download a data file while using Microsoft Internet Explorer, the user should select the desired file by placing the system pointer on the file name from the data list and pressing the right mouse button. This will display a pull-down menu from which the user should drag the mouse to highlight "Save target as ..." and release the mouse button. Internet explorer will then prompt the user to specify the name and location of where the selected data file should be saved.
Downloading a selected file with Netscape
To download a data file while using the Netscape browser, the user should select the desired file by placing the system pointer on the file name from the data list and pressing and holding the right mouse button. This will display a pull-down menu from Netscape. The user should drag the mouse to highlight "Save this link as ..." and release the mouse button. Netscape will then prompt the user to specify the name and location of where the selected data file should be saved. Different operating systems and newer versions of Netscape might work somewhat differently.