Weather affects timing of some natural hazards—Seasonal patterns in earthquakes and volcanic erupt…

[OKIsItJustMe]

http://www.sciencenews.org/view/generic/id/336856/title/Weather_affects_timing_of_some_natural_hazards

Weather affects timing of some natural hazards

Seasonal patterns in earthquakes and volcanic eruptions can be linked to rain and snow

By Devin Powell and Alexandra Witze
Web edition : 5:02 pm

SAN FRANCISCO — If you want to know the chance of an earthquake in the Himalayas or a volcanic eruption in Iceland, check the calendar. Seasonal patterns of rainfall and snowfall can affect how often quakes and volcanoes go off, scientists reported December 8 at a meeting of the American Geophysical Union.

In the Himalayas, the weight of water from monsoon rains helps dampen seismicity for a few months each year, says geophysicist Thomas Ader of Caltech. Seismic records collected from 1998 to 2004 show that the number of quakes drops in the rainy summer months and rebounds when things dry out.

Water from monsoon storms runs off the mountains and into India, where its weight bends the Earth’s crust slightly. From season to season, this bending causes the surface to move back and forth, as recorded by Global Positioning System stations, in time with the rise and fall in earthquake frequency.

Calculations by Ader and his colleagues suggest that the flexing eases the stress on the fault where two tectonic plates collide beneath the Himalayas. This change in stress is quite small — less than a hundred-thousandth of the stress caused by the motion of the plates. But it lasts for months, perhaps giving the earthquakes time to slowly incubate.

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[Lint Head]

1. Where water goes does impact the earth. Water is heavy.

http://www.nytimes.com/1996/03/03/news/dams-for-water-supply-are-altering-earth-s-orbit-expert-says.html

[kestrel91316]

2. When we have "earthquake weather" I often wonder if it's due to the

soil getting hot enough to drive out a substantial amount of water and therefore weight. People on DU have speculated, and at first I pooh-poohed it, but it gives one pause......

Whenever it gets unusually hot for whatever the season is, we in SoCal know to be more alert.

[XemaSab]

3. Earthquake weather's not just hot

October 17th was warm and hazy. According to Weather Underground, at the time of the quake it was 79 degrees with 40% humidity.

It was kinda muggy, but not oppressively so. Not cloudy, but the right mix of atmospheric moisture, pollution, and PM in the air to make you go "Hmm...."

It was the kind of day that seems like it should be a beautiful day, but it was sort of not. :P

[OKIsItJustMe]

5. I’d never heard of “Earthquake Weather” before

However, it seems to me that we would be talking about a dry spell, and not a single dry day.

[FirstLight]

4. that is too cool...

I am awed and yet not surprised that the planet is so interconnected... just goes to show you how we humans think we can change or effect things in some ways so arrogantly, and yet ignore the connections when we screw with the climate on a global scale. how much do you think the weight of those icecaps keep certain plates at the poles in a relatively quiet state? how much movement does it take to throw us off our orbit? it's amazing...