3 ms·

Anyone know of a group or website which is tracking the incidence and intensity of earthquakes over time?

by blueprint 10y ago

itcmcgrath 10y ago
http://quakes.globalincidentmap.com/ http://quakes.globalincidentmap.com/
- blueprint 10y ago
  I'm more looking for a study that tracks an increase or decrease in their intensity and magnitude over time. I would need to scientifically study and analyze the data at the link you kindly shared in order to see that.
deleted 10y ago
[deleted]
deleted 10y ago
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jamestnz 10y ago
Not sure if suitable for your purposes, but GeoNet. They use a network of digital seismic stations. Whenever seismic waves propagate, doing a time-analysis of when they passed under each station can tell you where the quake occurred. This is augmented with crowd-sourced "felt reports". Literally within seconds of a shake, the preliminary report hits their website, and its confidence level increases over the next few minutes as more data reports in. I believe their online (open) data set now catalogs all NZ-region earthquake events from like the last 80 years or something. Pretty neat. Here is the page for the big one of 6 hours ago, not to be confused with the dozens of also-large aftershocks following it: https://www.geonet.org.nz/quakes/region/newzealand/2016p858000 https://www.geonet.org.nz/quakes/region/newzealand/2016p8580...
- blueprint 10y ago
  I'm more looking for a study that tracks an increase or decrease in their intensity and magnitude over time. I would need to scientifically study and analyze the data at the link you kindly shared in order to see that.
cossatot 10y ago
http://www.globalcmt.org/ http://www.globalcmt.org/ Scroll to the bottom and look at the chart of cumulative energy (moment) release over time. This is probably the easiest visualization what you're looking for without going to scientific papers. It only goes back to the 1970s though. The big steps are the Sumatran earthquakes and Tohoku (Japan). There were some equally big steps in the 1950s. As far as I know (and I do this professionally) there is no evidence for any real variation in the global, time-averaged rate of earthquake occurrence or energy release. However the time window to average over has to be several decades to centuries depending on how comfortable one is with noise. Any individual segment of a fault will have an earthquake repeat time (for a significant earthquake) of hundreds (San Andreas fault) to tens of thousands of years, and is lots of evidence for clusters of earthquakes on individual faults or sets of faults, but this is mostly a local effect--the stress changes in the crust caused by an earthquake can basically load nearby faults and affect when they will have the next earthquake. But again, this is for the most part local (<100 km). Globally, earthquakes are essentially unrelated. That a big one may hit Chile and then Japan in short order is happenstance as far as the seismological community is concerned (though it's not dogma, and long-distance 'teleseismic' triggering is investigated--it just doesn't seem to be a big deal). However, earthquakes in the news aren't a good reflection of global seismic statistics. Earthquakes like the Italian events (M6-6.6) over the past few months (and years) occur every day, but mostly in the ocean basins and don't affect people other than shaking some palm thatch roofs in Vanuatu. The most deadly event (minus tsunami) in my lifetime was the Haiti earthquake in 2010, killing ~200,000 people, and it was a pretty routine, moderate-magnitude event. It just hit an incredibly vulnerable population.
- blueprint 10y ago
  You're the real MVP. Thanks for your understanding of my question and the info. I get what you're saying about cumulative energy release over time and it's interesting to note the effect that earthquakes' periodicity has on how we need to sample the data. Very useful.

Anyone know of a group or website which is tracking the incidence and intensity of earthquakes over time?

itcmcgrath 10y ago

http://quakes.globalincidentmap.com/ http://quakes.globalincidentmap.com/

blueprint 10y ago
I'm more looking for a study that tracks an increase or decrease in their intensity and magnitude over time. I would need to scientifically study and analyze the data at the link you kindly shared in order to see that.

deleted 10y ago

[deleted]

deleted 10y ago

[deleted]

jamestnz 10y ago

Not sure if suitable for your purposes, but GeoNet. They use a network of digital seismic stations. Whenever seismic waves propagate, doing a time-analysis of when they passed under each station can tell you where the quake occurred. This is augmented with crowd-sourced "felt reports". Literally within seconds of a shake, the preliminary report hits their website, and its confidence level increases over the next few minutes as more data reports in. I believe their online (open) data set now catalogs all NZ-region earthquake events from like the last 80 years or something. Pretty neat. Here is the page for the big one of 6 hours ago, not to be confused with the dozens of also-large aftershocks following it: https://www.geonet.org.nz/quakes/region/newzealand/2016p858000 https://www.geonet.org.nz/quakes/region/newzealand/2016p8580...

blueprint 10y ago
I'm more looking for a study that tracks an increase or decrease in their intensity and magnitude over time. I would need to scientifically study and analyze the data at the link you kindly shared in order to see that.

cossatot 10y ago

http://www.globalcmt.org/ http://www.globalcmt.org/ Scroll to the bottom and look at the chart of cumulative energy (moment) release over time. This is probably the easiest visualization what you're looking for without going to scientific papers. It only goes back to the 1970s though. The big steps are the Sumatran earthquakes and Tohoku (Japan). There were some equally big steps in the 1950s. As far as I know (and I do this professionally) there is no evidence for any real variation in the global, time-averaged rate of earthquake occurrence or energy release. However the time window to average over has to be several decades to centuries depending on how comfortable one is with noise. Any individual segment of a fault will have an earthquake repeat time (for a significant earthquake) of hundreds (San Andreas fault) to tens of thousands of years, and is lots of evidence for clusters of earthquakes on individual faults or sets of faults, but this is mostly a local effect--the stress changes in the crust caused by an earthquake can basically load nearby faults and affect when they will have the next earthquake. But again, this is for the most part local (<100 km). Globally, earthquakes are essentially unrelated. That a big one may hit Chile and then Japan in short order is happenstance as far as the seismological community is concerned (though it's not dogma, and long-distance 'teleseismic' triggering is investigated--it just doesn't seem to be a big deal). However, earthquakes in the news aren't a good reflection of global seismic statistics. Earthquakes like the Italian events (M6-6.6) over the past few months (and years) occur every day, but mostly in the ocean basins and don't affect people other than shaking some palm thatch roofs in Vanuatu. The most deadly event (minus tsunami) in my lifetime was the Haiti earthquake in 2010, killing ~200,000 people, and it was a pretty routine, moderate-magnitude event. It just hit an incredibly vulnerable population.

blueprint 10y ago
You're the real MVP. Thanks for your understanding of my question and the info. I get what you're saying about cumulative energy release over time and it's interesting to note the effect that earthquakes' periodicity has on how we need to sample the data. Very useful.