The esteemed Ira Leifer is usually more interested in small steady emissions of methane (=bubbles) because they signal hydrocarbon deposits. I e-asked, “Can the same or similar sensors be used to measure volcanic gas emissions?”
A reasonable estimate is that probably 60% of the gases emitted from a volcano would likely be steam, albeit very hot. Water vapor itself is not that interesting, but what vulcanologists watch for is a persistent change in volume or in proportions of other gases like carbon dioxide, sulfur dioxide and a host of others.
An Australian colleague claims that Indonesia does virtually no (zero) monitoring of volcanic gases. If true, that does not seem like the best policy for a nation with (depending on how you count) between 76 and 178 active volcanoes. A cynic might describe Indonesia as 18,000 islands with 180 active volcanoes inhabited by 250,000,000 humans many of whom prefer to live on coastlines and near calderas.
To the considerable annoyance of shipping companies there are oil and gas wells in the Sunda Strait. The Sunda Strait is not especially wide – or it would not be a strait. The distance between the southeastern edge of Sumatra and the northwestern edge of Java is barely 30 kilometers. While the strait being narrow and having islanda and getting fairly shallow at the eastern end were somewhat attractive for a bridge project, tides and storms create additional complexities. It is very unclear [to me] whether a large, deep-draft ship would be be influenced by a tsunami moving through the eastern end of the Sunda Strait. I am informed that the USS George Washington [CVN-73] did transit the Sunda Strait July 6, 2011. The narrowest part of the route was 2 kilometers and the shallowest section was 18 meters. The GW’s maximum navigational draft is 37 feet – coupled with a length of 1040 feet at the waterline and a displacement 104,200 long tons that makes for a slow and stressful passage.
I also e-asked, “Would you think there would be any chance that sensors on the marine wells might have detected warning signs?”