Saturday, March 12, 2011

Will the Japan earthquake trigger other earthquakes?

Yesterday a powerful earthquake struck Japan (8.9 on the Richtor Scale), the fifth most powerful earthquake ever recorded. It's causing some to revisit doom scenarios with strings of earthquakes causing massive earth changes and the pole shift. It would make some sense that shaking the planet in one place would cause weak places elsewhere to shake and trigger earthquakes elsewhere. But, just because something seems like it would make sense doesn't make it correct. So, let's take a look at what evidence exists about this question.

The first video below is an example of someone drawing together questionable evidence and coming to the conclusion of a looming major earthquake. The thing is she posted that video on March 9, and the earthquake occurred on March 11. I'm sure she's patting herself on the back about giving such a prescient warning, even though the information she gives has little credibility. She included a clip of physicist Michio Kaku predicting that "within our lifetime" one of a list of major cities (all of them on tectonic plates) will be destroyed. She took that as proof that "they" were giving "us" a veiled warning, but in truth that warning was akin to predicting the sun will rise in the morning.

Chile Earthquake Altered Earth Axis, Shortened Day and NASA Details Earthquake Effects on the Earth describe some details to the effects massive earthquakes have had on the earths axis, and on the rate of rotation of the planet. The articles are concerned with the large earthquake in Chile last year, and another large earthquake in Indonesia in 2005. In both cases the earthquakes were strong enough to reduce the length of the day and change the axis of the planet.

Ah.. okay, one could suppose that with a more massive earthquake that the axis of the planet could change enough to induce a pole shift. Maybe. Depends on what mechanism it is that causes pole shift. The shifting of the poles was discovered (so far as I know) in the 1950's by scientists taking core samples across the ocean floors. They found bands of the earths crust had different magnetic orientation, giving evidence that the north pole had not always been at the north pole, but sometimes is at the south pole. I recently found a video by a scientist talking about variations in the magnetic field: Tracking Variations in the Earth's Magnetic Field

Increase in Microearthquakes in California Found After Chilean Quake reports that "By studying seismographs from the earthquake that hit Chile last February, earth scientists at the Georgia Institute of Technology have found a statistically significant increase of microearthquakes in central California in the first few hours after the main shock. The observation provides an additional support that seismic waves from distant earthquakes could also trigger seismic events on the other side of Earth." The website helpfully listed out a few related articles: Big Earthquakes Spark Jolts Worldwide, Large Earthquakes Trigger A Surge In Volcanic Eruptions, and San Andreas Affected By 2004 Sumatran Quake; Largest Quakes Can Weaken Fault Zones Worldwide

Japan Earthquake Triggered Volcano Eruption In Russia? covers a report that perhaps maybe possibly the Japan earthquake has triggered a volcano eruption in Russia.

Another concern is whether geothermal drilling or hydraulic fracturing can cause earthquakes. How Does Geothermal Drilling Trigger Earthquakes? Goes over evidence from a mine in Switzerland (which was shut down after it triggered earthquakes) and a mine in the Geysers area of Northern California that's routinely triggering small earthquakes. The method discussed is pumping water underground into rock that's been heated by magma intrusions (e.g. from "failed volcanos"), the water is heated by the hot rocks, becomes steam, and drives a turbine to generate electricity. Geothermal power is one of the cleaner ways to generate electricity. At some installations they fracture the underground rock and the human induced activity "changes the stress field" underground, causing a change in the rate of earthquakes.

It turns out there is a lot of scientific evidence suggesting large earthquakes can trigger other earthquakes, or even volcanos. The next question is whether the fault zone I live in (the famous San Andreas fault is just a couple miles from me) is likely to be triggered by the Japan earthquake.

Fortunately the US Geological Survey runs a nice website showing earthquake data in real time. It indicates there are small earthquakes occurring in California, but that's normal. What stands out on the earthquake map is it looks very quiet with fewer earthquakes than normal. The articles referenced earlier indicate there can be triggering of small earthquakes elsewhere. And sure enough there are a few 1-2 scale earthquakes which have happened. But it doesn't look like an abnormal rate of them, and they've occurred in the most likely places. For example near Mammoth Lakes, in the Geysers area, and in the mountains south of Gilroy.

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