3.6 Earthquake and USGS

SoCal Sam

Lunatic Member
There was a 3.6 earthquake near my home which is not anything to worry about. There was a deep rumble followed by a quick jolt and that was it. What was interesting to me was how fast the earthquake got posted to the USGS website. From time of quake to when I found the info in USGS was four minutes! What times we live in..
 
That is quick. When the BIG ONE comes it is going to be tragic for California. I hope never to see it in my lifetime.
 
I live in a substantial earthquake zone and this year particularly since a pair of 6.4 quakes struck about 40 miles away it has been several good jolts every month since and all centered within a mile or so of the original 6.4's.. 2 days ago it kicked off a 5.1 in the same area when I was outside working on the house. Strangely I could hear it before I felt it, sounded like a big truck was idling in the driveway. My dog knew right away and started running around the house barking. Anyway 5 minutes and it was up on this site.
http://earthquake.alaska.edu/earthquakes
The state University here has had equipment to monitor quake activity since the "big one" hit in 1964 which in that case was 9.2. Somehow they must use monitoring stations to triangulate position, and strength and even depth which indicates the position in 3D. This site will show quakes all over the region even sometimes as far as Siberia. It is all based on data collected automatically from seismonitors stationed remotely.
Here is activity from this morning here for the past 2 weeks. I circled the one that I felt 2 days ago.
Capture.JPG
 
@Alobar, I used to work for the organization you linked to, from '88 to '90, in Fairbanks. It was the most interesting place that I have worked in my career. I only recognize one person on the staff page though. I remember someone bursting into the lab saying there was an earthquake in SF and the World Series went off the air. About 15 minutes later, I watched the Alaska State Seismologist measure the trace width on the pen & ink seismographs, then measure the distance from Fairbanks to SF using a string on a globe(!), plug the numbers into a calculator, and give an Richter estimate only .2 off from the final computer determination.

The holdup to computer analysis then was a need for human analysts to hand-pick the arrival times of shock waves, often from very noisy data. At the time, Japan had about 100 government-funded instrument 'stations', each in a vault at the bottom of a deep, deep concrete well. Some of our 100 or so stations were buried in the dirt as deep as someone could dig during an hour or so of expensive helicopter time, and took lots of experience to distinguish small quakes from wind, moving the trees, moving the roots...

Not that long ago, in geezer years at least, total elimination of the U.S. Geological Survey was part of a serious budget proposal. I'm glad they weathered that storm, and have made such progress with their software.
 
Read "8.4" by Peter Hernon . Fiction but very good explanation on earthquakes, faults, in the New Madrid Seismic zone. Damn scary if it ever occurs that way, Multiple 8+ earthquakes. Hope never to be in one. The crazies have a laugh about a 3.5. The one off the Mexico's coast, then below Mexico city. Plus a volcano erupting again. What's next?
 
@Alobar, I used to work for the organization you linked to, from '88 to '90, in Fairbanks. It was the most interesting place that I have worked in my career. I only recognize one person on the staff page though. I remember someone bursting into the lab saying there was an earthquake in SF and the World Series went off the air. About 15 minutes later, I watched the Alaska State Seismologist measure the trace width on the pen & ink seismographs, then measure the distance from Fairbanks to SF using a string on a globe(!), plug the numbers into a calculator, and give an Richter estimate only .2 off from the final computer determination.

The holdup to computer analysis then was a need for human analysts to hand-pick the arrival times of shock waves, often from very noisy data. At the time, Japan had about 100 government-funded instrument 'stations', each in a vault at the bottom of a deep, deep concrete well. Some of our 100 or so stations were buried in the dirt as deep as someone could dig during an hour or so of expensive helicopter time, and took lots of experience to distinguish small quakes from wind, moving the trees, moving the roots...

Not that long ago, in geezer years at least, total elimination of the U.S. Geological Survey was part of a serious budget proposal. I'm glad they weathered that storm, and have made such progress with their software.

I lived in San Fransisco and felt the quake. My residence was in the hills so there wasn't a lot of secondary shaking. The main shock was decent. I missed the Northridge quake but made it home in time for the aftershocks which were numerous and close. Northridge is about ten miles from my current home.
 
@Alobar, I used to work for the organization you linked to, from '88 to '90, in Fairbanks. It was the most interesting place that I have worked in my career. I only recognize one person on the staff page though. I remember someone bursting into the lab saying there was an earthquake in SF and the World Series went off the air. About 15 minutes later, I watched the Alaska State Seismologist measure the trace width on the pen & ink seismographs, then measure the distance from Fairbanks to SF using a string on a globe(!), plug the numbers into a calculator, and give an Richter estimate only .2 off from the final computer determination.

The holdup to computer analysis then was a need for human analysts to hand-pick the arrival times of shock waves, often from very noisy data. At the time, Japan had about 100 government-funded instrument 'stations', each in a vault at the bottom of a deep, deep concrete well. Some of our 100 or so stations were buried in the dirt as deep as someone could dig during an hour or so of expensive helicopter time, and took lots of experience to distinguish small quakes from wind, moving the trees, moving the roots...

Not that long ago, in geezer years at least, total elimination of the U.S. Geological Survey was part of a serious budget proposal. I'm glad they weathered that storm, and have made such progress with their software.
I understand they have been adding monitoring stations lately as there was some increased activity in the Brooks range in the past few years.
Interesting I missed that SF quake by about 6 months,been working there on the hi rises. That was pretty scary with those overpasses collapsing and the bay bridge.

I was in the Seattle quake in the late 90s I think. Was a good rip, but nothing close to the good Friday quake in Alaska. I was 9 years old in Fairbanks when that happened. We were far enough from the epicenter so no damage where I was. What I remember was just how long that thing shook. First one lasted 5 minutes I think, then the next one went on for a few more minutes, followed by another 5 minutes. This is my recall from 50 years ago so I may be incorrect. I remember them saying that was a "100 year event ", but that was over 50 years ago already! A 9.2 quake if that hits a major metropolitan center would be off the charts as to destruction and loss of life. Pray it never happens in our lifetime, that's all we can ask. Because it will happen.
 
A 9.2 quake if that hits a major metropolitan center would be off the charts as to destruction and loss of life.
Nuclear quake.. There was and 7.1 quake in Mexico today.. Mexico City area I believe.
 
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