A Bunch of Small Tremors in Bluffdale
In the last couple years that I've been somewhat regularly (at least 4 times a week) reviewing the USGS website for earthquake activity, https://earthquake.usgs.gov/earthquakes/map/, I haven't seen this much activity in a single location in the Salt Lake valley: 19 smallish quakes in the Bluffdale area.
I first noticed a smallish tremor reported last Wednesday (June 21), only a 1.4. This is too small for most people to even notice, and even the relatively few who might feel it, would question whether they actually felt it. (see the Wikipedia article for table of magnitudes https://en.wikipedia.org/wiki/Richter_magnitude_scale)
The day before there were three small tremors in the Heber City area, and one near East Carbon City.
But near Bluffdale, there have been 19 tremors between June 21 and the morning of June 27, ranging from magnitude 0.8 to 2.1.
I am not an earthquake expert, and while I don't think this is a sign of an immediate, impending large earthquake, it does seem a little ominous.
To me, it would appear that the pressure is slowly being released in one area.
That might seem like a good thing, release the pressure in small increments and avoid a larger, single release. This is a prevailing consideration, but it is only partly true. The energy difference between a 2 and a 4 is 1,000 times, so a lot of small earthquakes would have to happen to make a long lasting, significant decrease in the chance of a larger earthquake. More likely it would temporarily relieve some pressure.
However, what if by releasing pressure at one point it ends up causing greater pressure at another location in the nearby fault segment(s)?
While smaller quakes in an area could reduce the likelihood of a bigger quake in that same area, this is not always true because, as previously mentioned, it would take a large number of small quakes to equal the energy released in a larger earthquake. It could be that a larger earthquake is coming, or it could also be that the stress of the pressure is transferred to a nearby fault, which increases the pressure/stress at that fault. I look at this as kind of the reverse of aftershocks.
The theory is that aftershocks, which are smaller earthquakes that occur after a large earthquake, occur to reduce new pressure/stress points that occurred as a result of the larger earthquake. So, my thought is the reverse, that smaller earthquakes might end up causing more pressure on larger, nearby faults.
But, there is no way to actually prove it. And, there is no way to actually predict whether this is the case, and when a bigger earthquake may occur. It may be days, weeks, months, or years in the future before the pressure is released.
What I can't find it what faults or fault zone covers the Bluffdale area. To the north, and west of Salt Lake City is the West Valley Fault Zone, but the maps show this as too far north for Bluffdale to be a part of it. I'm guessing these small quakes must have occurred on the Salt Lake fault segment. If that is the case, could they then cause a transfer of pressure to another location on that segment?
As usual, I'm not trying to "cry wolf" but I am all about getting prepared. Despite what the scientists say (a 43% chance of a 6.75 or larger earthquake in the next 50 years), my personal (and unscientific) odds put the chances at about 40% this year, with the chances increasing 5-10% each year over the next seven years, with it topping out at 95% in seven years. I don't think it will be higher than that because I think there is always a chance that God would delay an earthquake if the people are repentant and return to him, but the chances would still remain high because when the people once again turn their backs on God the judgment could quickly come.
My intent is keep this as another reminder to get our homes in order and to become better prepared, both physically and spiritually.
---update 28 June 2017---
Add another tremor, a 1.2, to the Bluffdale count. That makes 20 in the last week. I wonder what's going on under the earth? It kind of reminds me of what I was noticing in Oklahoma a couple years ago, lots of little quakes. Except, the tremors in OK seemed to be related to the oil fracking, and the little quakes were more spread out. A 5.8 did strike near Pawnee, OK, on September 3, 2016.
I first noticed a smallish tremor reported last Wednesday (June 21), only a 1.4. This is too small for most people to even notice, and even the relatively few who might feel it, would question whether they actually felt it. (see the Wikipedia article for table of magnitudes https://en.wikipedia.org/wiki/Richter_magnitude_scale)
The day before there were three small tremors in the Heber City area, and one near East Carbon City.
But near Bluffdale, there have been 19 tremors between June 21 and the morning of June 27, ranging from magnitude 0.8 to 2.1.
I am not an earthquake expert, and while I don't think this is a sign of an immediate, impending large earthquake, it does seem a little ominous.
To me, it would appear that the pressure is slowly being released in one area.
That might seem like a good thing, release the pressure in small increments and avoid a larger, single release. This is a prevailing consideration, but it is only partly true. The energy difference between a 2 and a 4 is 1,000 times, so a lot of small earthquakes would have to happen to make a long lasting, significant decrease in the chance of a larger earthquake. More likely it would temporarily relieve some pressure.
However, what if by releasing pressure at one point it ends up causing greater pressure at another location in the nearby fault segment(s)?
While smaller quakes in an area could reduce the likelihood of a bigger quake in that same area, this is not always true because, as previously mentioned, it would take a large number of small quakes to equal the energy released in a larger earthquake. It could be that a larger earthquake is coming, or it could also be that the stress of the pressure is transferred to a nearby fault, which increases the pressure/stress at that fault. I look at this as kind of the reverse of aftershocks.
The theory is that aftershocks, which are smaller earthquakes that occur after a large earthquake, occur to reduce new pressure/stress points that occurred as a result of the larger earthquake. So, my thought is the reverse, that smaller earthquakes might end up causing more pressure on larger, nearby faults.
But, there is no way to actually prove it. And, there is no way to actually predict whether this is the case, and when a bigger earthquake may occur. It may be days, weeks, months, or years in the future before the pressure is released.
What I can't find it what faults or fault zone covers the Bluffdale area. To the north, and west of Salt Lake City is the West Valley Fault Zone, but the maps show this as too far north for Bluffdale to be a part of it. I'm guessing these small quakes must have occurred on the Salt Lake fault segment. If that is the case, could they then cause a transfer of pressure to another location on that segment?
As usual, I'm not trying to "cry wolf" but I am all about getting prepared. Despite what the scientists say (a 43% chance of a 6.75 or larger earthquake in the next 50 years), my personal (and unscientific) odds put the chances at about 40% this year, with the chances increasing 5-10% each year over the next seven years, with it topping out at 95% in seven years. I don't think it will be higher than that because I think there is always a chance that God would delay an earthquake if the people are repentant and return to him, but the chances would still remain high because when the people once again turn their backs on God the judgment could quickly come.
My intent is keep this as another reminder to get our homes in order and to become better prepared, both physically and spiritually.
---update 28 June 2017---
Add another tremor, a 1.2, to the Bluffdale count. That makes 20 in the last week. I wonder what's going on under the earth? It kind of reminds me of what I was noticing in Oklahoma a couple years ago, lots of little quakes. Except, the tremors in OK seemed to be related to the oil fracking, and the little quakes were more spread out. A 5.8 did strike near Pawnee, OK, on September 3, 2016.
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