Search

The NOAA 2 environmental satellite and subsequent environmental satellites provide daily coverage of the earth in the visible (0.6–0.7 μm) and thermal (10.5–12.5 μm) spectral bands. The ground resolution of the very high resolution radiometer is 1 km at nadir. This improved resolution in the visible spectral band permits more detailed observations of snow features than were possible with the previous operational satellites. A visible band image from February 11, 1973, depicts the heavy snow cover in considerable detail in areas from Alabama to North Carolina. Digitized reflectance data from the study area have been compared with prestorm bare ground digitized reflectance data of February 6, 1973, to examine the relation of snow reflectivity to snow depths. A regression analysis of greatest brightness versus greatest snow depth for 201 data pairs produced a power correlation coefficient of 0.86. Reflectance values from snow deeper than 30 cm tended to be uniformly high; values from snow less than 30 cm tended to increase rapidly as snow depth increased.

The thickness and extent of the sediment cover in the Patuxent Estuary has been determined using a high-frequency, high-spatial resolution, shallow penetration, continuous seismic profiling system. From these data, an isopachous map was prepared The isopachous map provides the subbottom information required to determine optimum locations for placing test equipment on the river bottom Mud filled depressions, acoustically transparent to 12-kHz sound pulses, occur mainly to the north of Half Pone Point, and east of the present channel Based on the identification of first subbottom reflectors, these depressions are as much as 16 feet thick The dominance of the thicker deposits east of the channel and evidence of a submerged terrace indicates that either the channel has migrated to the west, or that the channel of the Patuxent River at this location was larger in the past and has subsequently filled in much of the material in the eastern edge Maximum penetration at the scarp of the submerged terrace was 36 feet beneath the water-sediment interface This study demonstrates the use of seismic profiling techniques for collecting and presenting data required for coastal engineering applications.