Print this pageMILKOV, ALEXEI V., Texas A&M University, GERG and Dept. of Geology and Geophysics, College Station, TX
ABSTRACT: 
Gas
Hydrate Stability in the Gulf of Mexico: Significance to Resource
Estimation, Geohazards, and Global Change
Models of gas hydrate stability for the northern Gulf of Mexico
continental slope address basic problems of gas hydrate geology. Resource estimation is
based on assessment of the volume of the gas hydrate stability zone and concentration in
sediments. Total volume of gas trapped in gas hydrate in the Gulf is estimated to be 100
times less previously predicted. However, structurally-control led accumulations of gas
hydrate on the rims of salt withdrawal basins could be economic in the future. Bacterial
gas hydrates in salt withdrawal basins are unlikely to represent a significant energy
resource because they are disseminated.
Bottom water temperature variations from seasonal changes and warm Loop Current eddies
could affect sea-floor gas hydrate stability in the upper 12 m of sediments. A thin but
extensive hydrate geohazard zone is hypothesized on the upper Gulf slope in 440-720 m
water depth. Petroleum exploitation may be impacted in this zone by sediment deformation
from repetitive cycles of gas hydrate formation and dissociation.
It has been suggested that release of methane from sudden decomposition of gas hydrates
could cause geologically rapid global change. The potential effect of a 100 meter sea
level drop on gas
hydrate stability across the slope is not significant. However, large
volumes of methane and other greenhouse gases could be released in response to an increase
in seafloor water temperature of ~ degrees C.
AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid