No. 110: Mar-Apr 1997
The potential for methane eruptions from offshore sediments to sink ships and down aircraft was proposed by W.D. McIver way back in 1982, in the Bulletin of the American Association of Petroleum Geologists. (SF#25/208) The source of methane-gas releases ("burps") is the rapid decomposition of methane hydrate, which exists in prodigious quantities in offshore sediments. Some geologists have estimated that there is twice as much methane in methane-hydrate deposits as in all terrestrial natural-gas fields. What makes methane hydrate potentially lethal is its instability. Landslides and small quakes can release huge plumes of methane bubbles into the ocean and thence into the atmosphere.
Ships might founder in the lowdensity froth of bubbles, and aircraft might be adversely affected, too. This is where TWA800 comes in.
R. Spalding, a scientist at Sandia National Laboratories has been monitoring mysterious atmospheric explosions and believes that some of these detonations are consistent with the atmospheric ignition of huge methane plumes. (Other detonations are due to meteors.) Spalding proposes the following scenario:
Supporting Spalding's theory are the many reports of light flashes, light streaks, and booming/rumbling sounds accompanying the disaster. But, methane burps are bizarre, and the properties of methane hydrate are so unfamiliar to most scientists and investigators of aircraft disasters that Spalding's idea has received scant attention.
(Spohn, Lawrence; "Earth 'Burp' Might Have Downed Jet, Scientists Says," Albuquerque Tribune, January 20, 1997. More appeared in the January 24, issue. Cr. R. Spalding)
Comment. The phenomena accompanying methane burps are well known to SF readers. First, there are the common offshore booms that have been reported for centuries (SF#3/283, SF#8/283) and; second, the large craters (up to 100 meters across) observed in seafloor sediments (SF#9/197).
The Albuquerque Tribune article mentioned several other specific atmospheric detonations that have attracted attention: Newfoundland (1978); Spain (1994; Poland (1995); and Honduras (1996). Often such events are noticed only by surveillance satellites. However, the 1996 Honduras event was seen and heard by many residents of the area. See the next entry.
Reference. Methane hydrate is abundant in offshore deposits but hard to study. See ESC9 in the catalog: Anomalies in Geology. Ordering information here.