Posted on 01/27/2019 9:53:18 AM PST by ETL
Unlike conventional plate boundary earthquakes, which violently release pent-up energy for seconds or minutes at a time, slow earthquakes do not release seismic waves and can endure for many months.
Although previous research suggests these slow-slip events occur in the region between an upper, brittle seismogenic zone and the more pliable underlying material, the physical mechanisms that generate slow earthquakes remain unclear.
To better understand these puzzling aseismic events, Kano et al. scrutinized geodetic records from beneath the Yaeyama Islands, which sit along southwestern Japan’s Ryuku subduction zone.
Using specially filtered Global Navigation Satellite System (GNSS) data from the GNSS Earth Observation Network System (GEONET) and Kyoto University networks, the team detected and analyzed the evolution of five slow-slip events between July 2010 and February 2013.
Their results indicate that although all five slow earthquakes occurred within the same portion of the fault and had nearly the same magnitudes, they evolved quite differently over time. In particular, the style of nucleation varied considerably between events.
In three of the five records, the slow earthquakes reached their maximum rate of slip within a few days, whereas the nucleation occurred much more slowly during the other two, which sputtered along for 25 and 45 days before rapidly accelerating.
The total durations of the slow earthquakes also differed substantially, from about 30 to about 95 days; their maximum slip rate varied from 0.4 to 1.2 meters per year.
The differences between the five recorded events suggest that the fault’s physical properties, such as friction and the distribution of fluid pressure, may vary over time or that the stress state prior to slow-slip nucleation can differ between events.
Additional studies describing the temporal and spatial evolution of slow earthquakes should help researchers constrain the physical properties of these plate interfaces and ultimately clarify how slow-slip events are generated. (Journal of Geophysical Research: Solid Earth, https://doi.org/10.1029/2018JB016072, 2018)
https://eos.org/meeting-reports/understanding-slow-slip-and-tremor-on-plate-boundaries
*ping*
Slow earthquake
A slow earthquake is a discontinuous, earthquake-like event that releases energy over a period of hours to months, rather than the seconds to minutes characteristic of a typical earthquake.
First detected using long term strain measurements,[1] most slow earthquakes now appear to be accompanied by fluid flow and related tremor,[2] which can be detected and approximately located using seismometer data filtered appropriately (typically in the 1–5 Hz band).
That is, they are quiet compared to a regular earthquake, but not “silent” as described in the past.[3]
Slow earthquakes should not be confused with tsunami earthquakes, in which relatively slow rupture velocity produces tsunami out of proportion to the triggering earthquake. In a tsunami earthquake, the rupture propagates along the fault more slowly than usual, but the energy release occurs on a similar timescale to other earthquakes.
https://en.wikipedia.org/wiki/Slow_earthquake
While not as described, could “fracking” allow for slow-quakes, to avoid a major earthquake?
Sorry, I have no idea.
But the following article might get into it. Hopefully, it doesn’t contain any liberal BS “science”.
Slow-Motion Earthquakes Caused by Natural Fracking?
By Becky Oskin, Senior Writer
June 18, 2014
https://www.livescience.com/46386-what-causes-slow-slip-earthquakes.html
Fracking. Everyone knows that...ha! Said it first.
Danb. Barely beaten...sigh.
When you’re going up against ETL, you have to be quick!
Thanks fieldmarshaldj.
Barely catastrophism.
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“Barely catastrophism” reminds me of vivisemisepulture, almost being buried alive.
I think you mean semi-vivisepulture. It's not as gross as gastrojejunocolic fistula can be, but I'd take that over semi-vivisepulture.
Yes, I think we’d all rather have champagne.
What's to unravel, not all of Gaia's orgasms are monumental and Earth shaking, sometimes they're are just slow rollers!
My mind went the “lubrication route” too.
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