Geology topics

R.E. Lombard

Publications and source records attributed to R.E. Lombard.

3 recordsLinked to original sources

USGS1986

Data on snow chemistry of the Cascade-Sierra Nevada Mountains

Snow chemistry data were measured for solutes found in snow core samples collected from the Cascade-Sierra Nevada Mountains from late February to mid-March 1983. The data are part of a study to assess geographic variations in atmospheric deposition in Washington, Oregon, and California. The constituents and properties include pH and concentrations of hydrogen ion, calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate, fluoride, phosphate, ammonium, iron, aluminum, manganese, copper, cadmium, lead, and dissolved organic carbon. Concentrations of arsenic and bromide were below the detection limit. (USGS)

Open-File Report↗

USGS1986

Channel geometry, flood elevations, and flood maps, lower Toutle and Cowlitz rivers, Washington, June 1980 to May 1981

The volcanic eruption of Mount St. Helens on May 18, 1980, triggered mudflows that deposited upwards of 15 ft of sediment in the channels of the lower Toutle and Cowlitz Rivers. The major population areas along the lower Cowlitz River (Kelso, Longview,Lexington, and Castle Rock) were not flooded, but the channel capacity of the river was seriously reduced and the potential for unusually high flood elevations from fall and winter storms was an obvious concern. The U.S. Army Corps of Engineers began dredging operations in June 1980 to alleviate the flood hazard. Surveys to monitor the effect of changes to the channel and flood plains that resulted from dredging and additional sediment inflow from the upper Toutle River basin were started in June 1980 and continued until May 11, 1981, when dredging operations on the Cowlitz River had been completed. (USGS)

Water-Resources Investigations Report↗

USGS1981

Channel conditions in the lower Toutle and Cowlitz Rivers resulting from the mudflows of May 18, 1980

During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream sites within the watershed were compared with samples collected during the same season in previous years. No detectable changes were noted in chemical characteristics. Precipitation samples collected immediately after the June 12-13 ash fall ranged in specific conductance from 20 to 41 micromhos per centimeter at 25C and in pH from 4.0 to 4.3 pH units. Stream samples collected during the May-June period ranged in specific conductance from 18 to 28 micromhos per centimeter at 25C and in pH from 6.7 to 7.5 pH units. Volcanic-ash samples were collected and analyzed for particle size, chemical composition, and weight. Significant differences in particle size of ash were found in samples from two separate eruptions. (USGS)

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