July 27th, 2018 is a busy day!

Station E1TX, operated by Texas Educational Seismic Project in Spring, Texas, has recorded multiple global earthquakes and volcanic eruptions today, 07/27/2018.  

Shown below: Seismograms recorded today, 07/27/2018 at Station E1TX, on an EQ1 Seismograph. Also shown is a map of the epicenters (highlighted in circles) of these earthquakes.


Epicenter of the July 27th, 2018 El Salvador M5.3 earthquake.
A closer look at the El Salvador seismogram recorded on the EQ1 Seismograph.
Epicenter of the July 27th, 2018 Offshore, Northern Atlantic Ocean M5.1 earthquake.
Comparing the N. Atlantic seismograms recorded on the EQ1 and Raspberry Shake Seismographs.

Recent Oregon Earthquakes

Station E1TX, operated by Texas Educational Seismic Project in Spring, Texas, has recorded recent earthquakes in the Cascadia Subduction Zone (CSZ).  The CSZ covers a large area reaching from Vancouver Island down towards Northern California.  Comparing these two independent events is intriguing because (1) both were of similar epicentral distances away from Station E1TX, and (2) their independent magnitudes are close in range (M5.6 and M5.3).

Shown below: Two recent seismograms recorded at Station E1TX, on an EQ1 Seismograph, of the Oregon earthquakes.  Also shown is a map of the epicenters (highlighted in circles) of these earthquakes.

American Geophysical Union – ABSTRACT SUBMITTED !

ABSTRACT SUBMITTED!! Texas Educational Seismic Project (Spring, Texas) and Boston College Educational Seismology Project successfully submitted our collaborative abstract recently.  The abstract (see below) was submitted for consideration of an oral presentation / poster session at the American Geophysical Union’s (AGU) National Convention this December, 2018, in Washington DC. We are currently crowd sourcing to fund travel expenses from Houston to Washington DC.  Would you like to help us continue our shared work efforts within Texas and New England?  All donations are tax deductible!!  >>>  GoFundMe Campaign HERE



Comparing Mexican Seismograms

Station E1TX, operated by Texas Educational Seismic Project in Spring, Texas, proximal to several tectonic plate boundaries.  This is an ideal location for recording earthquakes with less attenuation effects on the seismograms.  We record **many** earthquakes from Mexico, and most of those seismograms look very similar.  Do you have any ideas why??

Shown below: Several recent Mexican seismograms recorded at Station E1TX.  Also shown is a map of the epicenters (highlighted in circles) of these earthquakes.

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BYO Seismograph Experiment!

Shown below: The EQ1 Educational (LEFT) and Raspberry Shake (RIGHT) Seismographs, and a Shake Table (BOTTOM) for creating your own ground motion.



Bored on a hot or rainy day?  Wish to push the creativity of your children or students to the next step up?  Why not learn about why earthquakes occur AND how do seismic waves move thru the Earth?  Build your own seismograph**!  Students will gain a greater appreciation of how a seismograph (earthquake instrumentation) works, and a better understanding of recordings of ground motion that they see on seismograms.  Another nice benefit – this experiment showcases cross-disciplines integrated together: geology, engineering, geophysics, mathematics, and simple machines 🙂

Ask children, and adults, to design and construct a seismograph using common household and craft materials provided. Once completed, they will demonstrate how their seismographs record motion.  A plus it to test each design on a Shake Board which can simulate ground motion during an earthquake – this FUN-tastic!

Suggested list of materials for this exercise:

  • masking tape and/or duct tape
  • weights or sinkers
  • empty paper towel rolls or toilet paper rolls
  • coil springs
  • straws
  • paper
  • paper plates
  • paper cups
  • pipe cleaners
  • marbles
  • pens and pencils
  • bouncy ball for demos
  • string or wire
  • empty bottles or boxes
  • scissors
**This experiment has been adapted by existing curriculum from Boston College’s Educational Seismological Project

We have the Seismogram to prove it!

At Station E1TX, we recorded the 09072018 Alaskan earthquake. The interpreted seismogram, below, represents the M6.0 earthquake 5780kms away near Chernabura Island, AK.  The event occurred at 14:16hrs UTC and had a focal depth of 17kms.  Surprisingly, the Raspberry Shake seismometer recorded many more wave phases than its competitor, the EQ1 Seismograph.  Amazing – note how small the amplitudes of the wave phases on the RS seismogram interpretation.

Comparing Seismograms of the 19072018 14:16hrs UTC M6.0 Alaskan EQ: Top (red): EQ1 Seismograph, Below (blue) Interpreted Raspberry Shake seismogram


TEACHING MOMENT: Effects of Magnitude and Epicenter Proximity

Today, 19 July 2018, Station E1TX recorded two moderate-to-large earthquakes of similar magnitudes but vastly different epicentral distances.  At 13:31hrs UTC, a M5.7 earthquake occurred offshore Mexico, and less then an hour later at 14:16hrs UTC a M.6.0 earthquake rattled Alaska.  Compare the screenshots from the EQ1 Seismograph with both events captured.  Lastly, take a look at the amplitude and variation in wave phases between the two seismograms.

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TEACHING MOMENT: Textbook Seismogram

An active morning for the Ring of Fire! A beautiful, textbook example of wave forms arriving at Station E1TX.  The interpreted seismogram, below, represents the M5.7 earthquake 858 miles (54kms) away near Huajuapan de Leon, Mexico.  The event occurred at 13:31hrs UTC and had a focal depth of 34 miles.


Double Trouble in the GoM

The day (17July2018) is only half over, but two earthquakes have already shaken the Gulf of Mexico.  At 08:16hrs UTC, a small M3.4 earthquake occurred offshore Dominican Republic followed by a moderate M5.0 earthquake at 08:54hrs UTC near Coalcoman de Matamoros, MX.  Both earthquakes are shown on the map below.  Also shown are the EQ1 and Raspberry Shake’s seismograms recorded from each event.  NOTE that the Raspberry Shake seismogram has a stronger signal:noise ratio in the higher frequencies (Dominican Republic earthquake) than the EQ1 Seismograph.  Each image is captioned when the slideshow plays.

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What’s that buzzing?

Buzzzzzz…..watching both Yemen and Hawaii volcanic eruption earthquakes arrive in Texas as I am typing….


Shaking the Gulf of Mexico

This morning, on 15072018 at 11:27hrs UTC (06:27 am CST), a small M3.7 earthquake rattled Puertro Rico.  A similar seismogram was recorded on both the E1TX Seismograph (shown in red) and Raspberry Shake (shown in blue). A 3.0 to 6.0 Hz bandwidth filter was applied to the Raspberry Shake seismogram.

Comparison of seismograms from the 15July2018 11:27hrs UTC Puerto Rico earthquake.



I see you running on the treadmill – when you began running, and when you completed your time goal.  Furthermore, I can show you the specific frequencies of the man-made seismogram.  On 13072018 and 09:46hrs UTC during the M6.4 Vanuatu Earthquake (specifically during the arrival of the Rayleigh and Love waves), the seismogram is partially convolved with a dominant “noise” factor as shown below.  The red circles denote frequencies from an actual seismic event, while the purple bracketed time shows the segment where a treadmill was running for 30 minutes.  The effect on the seismic event can be seen as several lines at frequencies which are multiples of ~5.0.

This is an excellent example of how we may interpret “noise”, particularly high noise-to-signal ratio time segments.  When viewing the Spectrogram View, instead of the Wave Amplitude View, the convolution is obvious.  For Station E1TX, we used a bandwidth filter to reduce the effect…. we chose a 3.0 to 6.4 Hz bandwidth filter as an attempt to increase the signal-to-noise ratio (meaning enhancing the signal and dampening the noise). The unfiltered seismograms are as images 1 and 2; the last image is the filtered seismogram.

UNfiltered Wave Amplitude View Seismogram, Purple is bracketed noise; red is actual signal being detected.
UNfiltered Spectrogram View Seismogram, Purple is bracketed noise; red is actual signal being detected.
Raspberry Shake seismogram with 3.0 to 6.4 Hz bandwidth filter applied.