Fallout of thorium isotopes from the 1982 eruption of El Chichon volcano

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5622191

Barbod, T

Radiochemical measurements of the concentrations of the /sup 228/Th, /sup 230/Th, and /sup 232/Th have been carried out for a total of 38 individual samples of rain and snow collected at Fayetteville (36 N, 94/sup 0/W), Arkansas, during the period between April 1982 and December 1983. The concentrations of /sup 228/Th, /sup 230/Th, and /sup 232/Th in a total of 9 composite rain samples, each covering a period of three months, have been also determined radiochemically. The thorium isotope data thus obtained were compared with the results of measurements of the concentrations of uranium isotopes in these rain and snow samples, which were carried out in our laboratories by previous investigators. The eruption of El Chichon volcano in Mexico occurred on March 28, 1982, and was followed by the second phase consisting of two major eruptions of April 3 and April 4, 1982. Marked increases in the concentrations of thorium and uranium isotopes were observed during the months of January and February 1983, followed by small peaks in April and May 1983. The concentrations of the /sup 23/2''Th and /sup 238/U in rain samples collected at Fayetteville, Arkansas, decreased steadily during the second half of 1983. The ratios of /sup 228/Th//sup 232/Th and /sup 230/Th//sup 232/Th in rain also showed a marked increase during the first half of 1983. These results indicate that the thorium and uranium isotopes in rain during the first half of 1983 had their origin in a large amount of volcanic ash materials injected into the stratosphere by the 1982 eruption of El Chichon volcano in Mexico.

• Research Organization: Arkansas Univ., Fayetteville (USA)
• OSTI ID: 5622191
• Country of Publication: United States
• Language: English

Related Subjects

500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
AIR POLLUTION
ALPHA DECAY RADIOISOTOPES
ARKANSAS
ATMOSPHERIC PRECIPITATIONS
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
DEVELOPING COUNTRIES
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL EFFECTS
EVEN-EVEN NUCLEI
FALLOUT
FEDERAL REGION VI
HEAVY NUCLEI
ISOTOPES
LATIN AMERICA
MEXICO
NORTH AMERICA
NUCLEI
POLLUTION
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
RAIN
SNOW
THORIUM 228
THORIUM 230
THORIUM 232
THORIUM ISOTOPES
USA
VOLCANOES
YEARS LIVING RADIOISOTOPES