Hey guys. Sorry I have not been doing many blog posts or videos lately. Life has been pretty crazy. However I have a new laptop on the way with a brand new $100 video editing software I am going to be using for my videos and for my website. I have been updating a few pages on my site here so always remember to browse around to see if anything was changed or added to. Now in the past day, at the time of writing this, there was a magnitude 7.1 earthquake that struck south of South America and south of the South Sandwich Islands. There has also been a sequence of three M3.0+ quakes near Glenwood Springs in Colorado. I will simply show some data for these events. Earthquakes do occur in Colorado from time to time so these quakes are not that crazy. However they do appear to be connected and I am currently unsure which fault they are striking on, if indeed they are tectonic in nature. Also Steamboat Geyser in the Norris Geyser Basin at Yellowstone National Park and Caldera erupted for the 30th time just a few days ago. This means 2018 is now the most active year ever on record. What could this mean for the infamous supervolcano? As always, please click the title of this post or "read more" to continue.
M7.1 South Sandwich Islands
On December 11, 2018 at 02:26UTC a magnitude 7.1 earthquake struck just south of the South Sandwich Islands and occurred at a depth of 164.7km. This is the third earthquake, magnitude 7.0 and above, that has occurred in the word in the past 12 days! That is a good amount of activity! The other two quakes were the 7.0 in Alaska and the 7.5 in New Caledonia. I wouldn't be surprised if larger quakes were approaching. Now in the image above we see the event page for the M7.1. The "Tectonic Summary" directly above was NOT written by me but by USGS. This M7.1 that recently occurred is only the 2nd M7.0+ to occur in the past 100 years!
In this image directly above, the M7.1 is marked with an orange circle. The orange triangle is the location of the closest seismic station to this event. It is station HOPE and it resides on the South Sandwich Islands within the II network. I am very thankful this event occurred in a very remote location! Although this was a large earthquake, it seems nobody felt it. Again, this is the third M7.0+ earthquake to strike the world in less than 2 weeks.
Below are the seismic plots for this event. There are going to be two helicorders and two 3-plot images generated from data provided by IRIS from stations HOPE, in the II network near the epicenter, and MCID, which resides in the WY network at Yellowstone. As always please remember to read chart labels first if possible and pay attention to any captions beneath any images.
Now I know this station, HOPE, is sort of far away from the epicenter but how the heck did this earthquake show such strong, dominant low frequencies around 0.05Hz to about 0.2Hz? In my opinion this almost looked like a low frequency event! I doubt it was though because I personally have never heard of a M7.1 low frequency earthquake. Regardless, this was a very interesting earthquake.
And here is the teleseism for MCID. Remember a teleseism is just the signal of a large earthquake that typically occurs at magnitude 5.5 and above and strikes 900km or more from the location of the station in question. Remember how the station closest to this M7.1, HOPE, saw dominant low frequencies of around 0.05Hz to about 0.2Hz? Well look at the spectral plot here. It seems to be showing low frequencies as usual, but it seems the frequencies rose a bit. Usually frequencies should drop with distance but it looks like this rose! Very interesting!
M3.2, M3.4, and M3.6 Strike Colorado
On December 11, 2018 there were three M3.0+ quakes that struck within a small area in Colorado, within only 1 hour and 14 minutes. They were all reported to have occurred at the same exact depth: 5.0km. So far there have been no other earthquakes detected besides these three. They were very interesting and occurred in a location that doesn't see many earthquakes. Of course they do occur, but I am unsure which fault these earthquakes are striking on. In the image above you can see the location of the three earthquakes.
The orange triangle marks the location of the closest seismic station to these quakes, O20A in the N4 network. Below I will first show the helicorder for this station and will then show the seismic plots along with the USGS event pages. All seismic plots you see were generated by myself using data from IRIS along with the seismic program SWARM.
The two images directly above show the first earthquake in this sequence. It was a magnitude 3.4 at 5.0km in depth. Notice the high frequencies. Also notice how long the earthquakes lasted! This M3.4 was felt by over 32 people! And that was only the people who decided to report this to USGS.
Here is the second, and strongest, earthquake to occur within this sequence. Note the same high frequency characteristics and long lasting coda. This was reportedly a magnitude 3.6 at 5.0km in depth. This occurred just over an hour after the first earthquake but this quake was reportedly felt by 130 people! Again, that is the number of people who REPORTED feeling this earthquake to USGS. Many people do not report earthquakes so whenever you see a number of felt reports just know it is likely many more people felt it.
Less than 3 minutes after the M3.6 the third earthquake of this sequence occurred. It was reportedly a magnitude 3.2 at, once again, 5.0km in depth. If the depth is correct for all three quakes, what is going on at that depth specifically? Very interesting. Notice this earthquake carried the same characteristics as the last two. Also nobody reported feeling this earthquake. It is likely people did feel this though but many of the felt reports probably went towards the M3.6 since the timing was very close.
So what is going on in Colorado? This was a very intriguing sequence of earthquakes. Three of them occurring in only 1 hour and 14 minutes with all of them supposedly occurring at the same exact depth. Also their characteristics seemed almost identical and their codas (coda = end tail of an earthquake) were pretty long lasting.
Steamboat Breaks All-Time Record
On December 8, 2018 Steamboat Geyser broke the all-time record of 29 eruptions in one year, which occurred in 1964. The current all-time yearly record, as of December 11, 2018, is now 30 eruptions in one year which occurred in 2018. There could be a couple more eruptions before this year ends but the record has been set! Now this recent Steamboat eruption did break the all-time record, yes, but it was much smaller than any other eruptions in 2018. Is it ending? Or is it simply that the blockage has been cleared which was causing the larger amplitudes? I don't know. However I did a video on it so you can watch it below or CLICK HERE to go to the video's page. If you would simply like to see the plots of this eruption, please goto the "Seismic Events" drop down menu above and click "Steamboat (2018)". The most recent eruptions will always be at the top. This is the end of the blog post so have a great day! I will try to be back soon (even sooner if something interesting occurs).
Ben Ferraiuolo is a fast learner and someone who will always stand for the truth. Visit "About Me" for more!