Filters: Tags: volcanic landforms (X)
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The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. Lava domes were extruded during the subsequent eruptive periods of 1980-1986 and 2004-2008. During 2017, U.S. Forest Service contracted the acquisitions of airborne lidar surveys of Mount St. Helens and upper North Fork Toutle River basin, part of a larger 2017-2018 survey of the Gifford Pinchot National Forest. The U.S. Geological Survey combined and reprojected 81 raster datasets, provided by the U.S. Forest Service in October 2018, into a single digital elevation model (DEM) of the ground surface, including beneath forest cover (that is, 'bare earth')....
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: ALS,
Cascade Range,
Cowlitz County,
DEM,
Ecology,
Two empirical simple linear regression models were developed from SedCam imagery and concurrent physical sediment samples over a 20-month period at the East Branch Brandywine Creek gage (USGS 01480870). The image files included here are a subset, used in the calibration dataset for these regression models. Models relate the explanatory variable, Rmax (maximum digital number of the red band, which peaks at a wavelength of 590 nanometers) to point and cross-sectional mean sample response variables (milligrams per liter). These regression models predict suspended-sediment concentration from a non-contact sediment surrogate technique to improve surface water monitoring operations. Files include Nikon Electronic Format...
The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. The eruption produced mudflows in the South Fork Toutle River basin, which drains the western slopes of the volcano. Orthophotography was acquired shortly after the eruption (June 19 and July 1). Survey extent includes South Fork Toutle River, from its headwaters at Talas and Toutle Glaciers to its mouth at the confluence with North Fork Toutle River near Toutle, Washington. In 2004, Photo Sciences, Inc., under contract to the U.S. Geological Survey (USGS), used softcopy photogrammetry techniques to produce a contour map, breaklines, and masspoints. A USGS...
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