What is this? There are many recordings at E1TX which I cannot associate with: global seismicity*, known time frames of local construction, news reporting of local earthquakes. Look at this example – the extracted waves look similar to S waves, could they be S waves? There was NO global earthquake with a magnitude > 4.0* during the extracted time period. Things which make me THINK!
Devastating 7.5 Earthquake in Afghanistan This Morning, October 26 at 09:09 UTC
While the West was sleeping, a magnitude 7.5 earthquake, depth 212 km, occurred this morning in the Hindu-Kush Region in Afghanistan. Although local flooding has obscured the visibility of this earthquake on the EQ-1, the extracted seismogram is clearly evident. See below for the screenshot, basemap of the epicenter and the extracted recorded ground motion.
TX-ESP is getting new neighbors, a new SUPER Highway and more according to the seismometer. Take a look at the screenshot and extraction of recorded ground motion at the start of the Oct 24-25 weekend. On the screenshot, note the recorded waves ABOVE the red lines – this ground motion is due to explosives being used to clear land for the new homes. The quick explosions were audible at E1TX. Good to see that the un-sophisticated EQ-1 instrument is working properly.
Hurricane Patricia Crosses South Texas
As Hurricane Patricia moves Wet to East across South Texas, you can observe (1) the increase in amplitude, and (2) the slow time drift in the EQ-1 seismometer. The time drift is annotated on the screenshot with 2 red circles – one on the screenshot and the other on the computer’s internal clock**. The times should match; however, the seismogram recorded data has an apparent arrival approximately 1 hour later than the actual time (shown on the bottom right). The extracted seismogram is the ground motion record from 1200 to 1300 hrs UTC.
**E1TX internal computer is set to display time in UTC.
In Spring, north of Houston, we are experiencing moderate flooding at 1602 hrs UTC.
Landfall of Hurricane Patricia was estimated to occur sometime between 0600 and 0800 hrs CST (1100 to 1300 hrs UTC) near Puerto Vallarta, Mexico. Below, the ground movement associated with the world’s largest hurricane ever was/is recorded(ing). At this time, 11:25 hrs CST, the Low Pressure front has NOT hit the greater Houston area.
A 7.1 Magnitude Earthquake Wasn’t Recorded at E1TX on October 20, 2015 21:52 UTC.
The depth was 127km at the epicenter in the Vanuatu Islands. Why didn’t the LARGE earthquake record on the EQ-1 seismometer? Was the earthquake too deep? Is Houston in the P, S waves “shadow zone” ? What you do not see is just as important to the story as what you do record.
Below is the screenshot of EQ-1 seismometer and extracted waves recorded during the time period from 21:25 to 22:25 hrs CST. On the screenshot, note the waves recorded above the red lines. This ground motion is due to local highway construction. The RED arrow indicate the official time of the event.