It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
There was debate about the origin of the earthquakes in Arkansas way back when. We knew what was causing them.
The stronger the spatial clustering, the larger the influence of small earthquakes on stress changes at the location of a future event as well as earthquake triggering. If earthquake magnitudes follow the Gutenberg-Richter law with b>D/2, small earthquakes collectively dominate stress transfer and earthquake triggering, because their greater frequency overcomes their smaller individual triggering potential.
Because large earthquakes modify stress over a much larger area than smaller ones, and because computing Coulomb stress changes requires a good model of slip distribution available only for large earthquakes, most studies have neglected the inﬂuence of “small” earthquakes.
• A triggered earthquakes size is independent of the magnitude of the triggering event (“mainshock”) as suggested by [Helmstetter, 2003]. This implies that the crust is everywhere close to failure, such that any small earthquake, triggered by a previous small one, can grow into an event much larger than its trigger
These results imply that a small earthquake can trigger a much larger earthquake. It thus validates our hypothesis that the size of a triggered earthquake is not determined by the size of the trigger, but that any small earthquake can grow into a much larger one [Kagan, 1991b; Helmstetter, 2003; Felzer et al., 2004]. The magnitude of the triggering earthquake controls only the number of triggered quakes
Although large earthquakes are much more important than smaller ones for energy release, small quakes have collectively the same inﬂuence as large ones for stress changes between earthquakes, due to seismic spatial clustering.
Can you prevent large earthquakes by making lots of small ones, or by "lubricating" the fault with water or another material?
Seismologists have observed that for every magnitude 6 earthquake it would take 32 magnitude 5's, 1000 magnitude 4's, 32,000 magnitude 3's (and so on for smaller earthquakes) to equal the energy of one magnitude 6 event. So, even though we always record many more small events than large ones there are never enough to eliminate the need for the occasional large earthquake.
As for "lubricating" faults with water or some other substance, injecting high pressure fluids deep into the ground is known to be able to trigger earthquakes to occur sooner than would have been the case without the injection. However, this would be a dangerous pursuit in any populated area as one might trigger a damaging earthquake.
M6.3 - 29km SW of Macquarie Island, Australia
2016-09-08 21:46:21 UTC
10.0 km depth
Bluff, New Zealand
1119.8 km (695.8 mi) SW
Invercargill, New Zealand
1139.0 km (707.7 mi) SW
Gore, New Zealand
1191.9 km (740.6 mi) SW
Queenstown, New Zealand
1281.1 km (796.0 mi) SW
Dunedin, New Zealand
1282.6 km (797.0 mi) SW