Interpreting Lake Mary Yellowstone Seismographs

I was looking at the Yellowstone seismographs this evening and was looking for assistance on reading these. One I am most curious about is the Lake Mary seismograph. Because these images are 160k each I will only display the first in the set and provide links to the next 6 if you want to look at them. What it seems to be is alot of background noise during normal daytime hours. I assume the readings are caused by tourist activity in the area. I could be dead wrong. It is simply a guess. The one of most interest is from the 14th. There seems to be alot of activity for a good part of the 24 hour period.

04-11-2005


04-12-2005

04-13-2005

04-14-2005

04-15-2005

04-16-2005

04-17-2005

I agree with your assessment regarding tourist activity. The seismometers are quite sensitive and must be picking up footsteps during these time periods.

Do you have an opinion when it comes to the April 14th one? The reason I put up a full week was for people to see how the days compared. Also to show how 4-14 stood out from the others.

It is interesting when you compare it to this Mount St. Helens seismograph from a couple days ago. The two are completely different. The St. Helens one shows what appears to be a great deal of rock fracturing.

Originally posted by Indy
Do you have an opinion when it comes to the April 14th one? The reason I put up a full week was for people to see how the days compared. Also to show how 4-14 stood out from the others.

I'm not a geologist nor an expert at reading these things, but since it looks so constant over an extended period of time, it could be indicative of other human activity, such as large vehicles or equipment movement, construction or something in the area. Or of course it could be some type of prolonged real seismic or geothermal activity.

The hours that the events took place and for the amount of time it took place would lead me to rule out human activity. It went on almost all night long and pretty strong.

Here is something cool for those that care to see what different types of tremors look like on a seismograph.

homepage3.nifty.com...

As a geologist this just looks like noise on the seismograms, caused by as people have already said, things like cars, people etc etc

Rock.. from 09:00 to 18:00 or so I could agree. But what about the one day where the activity runs all night long and heavy? The pattern of activity on the seismographs for everything else was pretty easy to pick up since it was about the same on all. It picked up during day hours and quit at sunset. This might sound stupid but what would rain look like on a seismograph?