Methane and radioactive isotopes in submarine hydrothermal systems
This thesis consists of two parts: 1) methane and 2) radioactive isotopes, especially radon, in submarine hydrothermal systems. Both parts deal with the use of these gases as tracers for mapping hydrothermal vents at sea, and with their relationships to other sensitive tracers such as helium, manganese, and temperature. Hydrothermal methane was used as a real-time tracer for locating new submarine hydrothermal systems along spreading axes, discovering new hydrothermal systems at two locations in Pacific Ocean: 1) 20/sup 0/S on East Pacific Rise, and 2) Mariana Trough Back-arc Basin. Methane shows good correlations with helium-3 and temperature with similar ratios in various hydrothermal systems, 3 to 42 x 10/sup 6/ for the methane to helium-3 ratio, and 3 to 19 ..mu.. cc/kg/sup 0/C for the methane to temperature anomaly. These similar ratios from different areas provide evidence for chemical homogeneity of submarine hydrothermal waters. A good correlation between methane and manganese appears to be associated only with high-temperature hydrothermal systems. Radioisotopes in the vent waters of 21/sup 0/N high-temperature hydrothermal system have end-member concentrations of 7.5 to 40 dpm/kg for Ra-226, 360 dpm/kg for Rn 222, 62 dpm/kg for Pb-210, and 19 dpm/kg for Po-210. The radon activity for this system is one order of magnitude lower, and the Pb-210 activity is one order or magnitude higher, than those a the low temperature Galapagos system. All these observations suggest that the high radon, and low Pb-210 activity observed in Galapagos system may originate from the extensive subsurface mixing and water-rock interaction in this system (direct injection of radon and scavenging of Pb-210).
- Research Organization:
- California Univ., San Diego (USA)
- OSTI ID:
- 5752591
- Country of Publication:
- United States
- Language:
- English
Similar Records
Submarine thermal springs on the Galapagos rift
/sup 238/U, /sup 226/Ra and /sup 210/Pb in some vent waters of the Galapagos spreading center
Related Subjects
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
520300 -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- (1989)
54 ENVIRONMENTAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKANES
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
ELEMENTS
ENERGY SYSTEMS
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GEOTHERMAL SYSTEMS
HEAVY NUCLEI
HELIUM 3
HELIUM ISOTOPES
HYDROCARBONS
HYDROTHERMAL SYSTEMS
ISOTOPES
LEAD 210
LEAD ISOTOPES
LEVELS
LIGHT NUCLEI
MANGANESE
MASS TRANSFER
METALS
METHANE
NUCLEI
ORGANIC COMPOUNDS
PACIFIC OCEAN
POLONIUM 210
POLONIUM ISOTOPES
QUANTITY RATIO
RADIOISOTOPES
RADIUM 226
RADIUM ISOTOPES
RADON 222
RADON ISOTOPES
REAL TIME SYSTEMS
ROCK-FLUID INTERACTIONS
SEAS
STABLE ISOTOPES
SURFACE WATERS
TEMPERATURE EFFECTS
TRANSITION ELEMENTS
UNDERWATER
YEARS LIVING RADIOISOTOPES