Geology topics

Research about Amchitka Island, Aleutian Islands

Source-linked reports with geographic coverage including Amchitka Island, Aleutian Islands.

7 recordsLinked to original sources

USGS1976

Radiochemical monitoring of water after the Cannikin event, Amchitka Island, Alaska, August 1974 and chemical monitoring from July 1972 to June 1974

Radiochemical data from the Arnchitka Island study area were obtained from water samples collected by the U.S. Geological Survey during August 1974. Tritium determinations were made on 18 samples, and gross alpha and gross beta/ gamma determinations were made on 12 samples. No appreciable differences were found between the data obtained during August 1974 and the data obtained before the Cannikin event. Chemical analyses were made on 4 samples collected in 1971, on 15 samples in 1972, on 11 samples in 1973, and 7 samples in 1974. Comparison of these analyses to analyses of samples collected before the Cannikin event indicates no changes outside of the seasonal range normally found at the sampling locations.

Alaska↗

USGS1976

Radiochemical monitoring of water after the Cannikin event, Amchitka Island, Alaska, May 1974

During May 1974, the U.S. Geological Survey collected water samples from Amchitka Island, Alaska. Tritium determinations were made on 99 water samples, and dissolved gross alpha and gross beta/gamma determinations were made on 34 water samples, No appreciable differences were found between the data obtained in May 1974 and the data obtained before the Cannikin nuclear explosion.

Alaska↗

USGS1973

Biochemical monitoring of water after the Cannikin event, Amchitka Island, Alaska, August 1973

Radiochemical data from the Amchitka Island study area were obtained from water samples collected by the U.S. Geological Survey during August 1973. Tritium determinations were made on 86 samples collected and gross alpha and gross beta/gamma determinations were made on 38 samples. The range of data for these samples was equal or less than the range of values obtained before the Cannikin event.

Alaska↗

USGS1972

Radiochemical monitoring of water after the Cannikin event, Amchitka Island, Alaska, January 13-April 5 , 1972

The U.S. Geological Survey collected 110 water samples from Amchitka Island, Alaska, between January 13 and April 5, 1972. Tritium determinations were made on all samples collected and gross alpha and gross beta/gamma determinations were made on 92 samples. The gross alpha and gross beta determinations when compared with previously determined ranges for fresh waters on Amchitka Island show no trends.

Alaska↗

USGS1972

Hydraulic tests in hole UAe-6h, Amchitka Island, Alaska

Inflatable straddle packers were used to isolate and test 14 intervals ranging from 39 to 258 meters (127 to 846 feet) each in hole UAe-6h. Packer seats were poor in part of the hole because of unstable wall conditions. Thus, some zones had to be tested several times. The static water levels in the intervals tested ranged from about 23 meters (71 feet) below land surface in the upper interval to an estimated 90 meters (295 feet) below land surface in the lower intervals, indicating a decreasing head with depth. The specific capacity of the hole from 85. 0 to 2,133. 6 meters (279 to 7,000 feet) was 1.94 cubic meters per day per meter (0. 11 gallon per minute per foot) of drawdown after the hole had been jetted at an average rate of 327 cubic meters per day (60 gallons per minute) for about 23 hours . Transmissivity computed from the recovery of water level after jetting stopped was 0.60 cubic meter per day per meter (48.3 gallons per day per foot). The relative specific capacities of isolated intervals ranged from 0.004 cubic meter per day per meter (less than 0.001 gallon per minute per foot) of drawdown to 0.430 cubic meter per day per meter (0.024 gallon per minute per foot) of drawdown.

Alaska↗

USGS1972

Water inflow into hole UA-1, Amchitka Island, Alaska

Chemical composition of water samples, temperature of inflow water, and theoretical calculations were compared to evaluate the water-contributing intervals to the zone to be mined--1,782.8 to 1,798.6 meters (5,849 to 5,901 feet)--in hole UA-1, Amchitka Island, Alaska. Chemical composition and temperature of inflow water indicated the contributing zones to have a mean depth of 1,670 meters {5,478 feet) and 1,726.7 meters (5,665 feet), respectively. An unrestricted inflow rate based on this data was calculated to be 380 cubic meters per day (70 gallons per minute) which compared well with the measured restricted-inflow rate of 164 cubic meters per day (30 gallons per minute) for hole UA-1 at the end of November 1970.

Alaska↗

USGS1971

Calculated in situ rock density from gravity observations, UA-1 (Cannikin) emplacement hole, Amchitka Island, Alaska

Gravity observations were made on the ground surface and at a depth of 5,854 feet in drill hole UA-1. Two attempts to measure the free-air gradient utilizing the headframe over the drill hole were unsuccessful owing to mechanical vibrations in the structure. Because of the uncertainty in the measured free-air gradients these values were discarded and the average value (0.09406 mgal/ft) was used in the calculations. The calculated in situ bulk density is 2.36 g/cc. The weighted average bulk density determined from 47 core samples taken in the adjacent UAE-1 drill hole is also 2.36 g/cc. An analysis of selected portions of density logs provides an in situ bulk density of 2.37 g/cc.

Alaska↗