As the title hints, this article discusses the possibility that some seismic events result from movements of low pressure weather systems, (troughs) through a region with geophysical instability resulting in ground shear seismic quakes. A history of storm-based seismic events can be correlated to movement of significant trough propagated mesoscale convective systems (MCSs), bombogenesis, hurricanes and typhoons, under ideal thermal conditions.
As referenced from a Nature Geoscience NGEO659 technical report, “According to our model, the tidal changes in air pressure cause air and water in the sediment pores to flow vertically, altering the frictional stress of the shear surface; upward fluid flow during periods of atmospheric low pressure is most conducive to sliding. We suggest that tidally modulated changes in shear strength may also affect the stability of other landslides, and that the rapid pressure variations associated with some fast-moving storm systems could trigger a similar response.”1 (See slideshow.)
1 Landslide movement in southwest Colorado, triggered by atmospheric tides, Nature Geoscience NGEO659 News, William H. Schultz, Jason W. Kean, and Gonghui Wang (November 2009)
The previous figure from the “Landslide movement in southwest Colorado, triggered by atmospheric tides,” paper indicated a consistent and repeatable inverse relationship between atmospheric pressure and landslide rates, in other words, as low pressure systems move through, landslide rates increased.
Both tornadoes and earthquakes are separate events, with significantly different origins, yet have one attribute in common, the ability to destroy human habitations and natural environments. To determine how much large scale or severe weather patterns can affect unstable geologic formations requires significantly more scientific research.
In a simpler comparison, it is fairly well known, by both geophysical scientists and the general US football audience, that Seattle Seahawk fan noise created three well documented earth quake events in their stadium during NFL playoff games. Most recently in 2014, Seahawk fans produced an earthquake monitored by 3 remote sensing stations during the Lynch touch down against the New Orleans Saints. Announcers even joke that this is the Seahawks legal 12th man on the field, as opposing teams can be so intimidated by the thunderous noise. The Weather Channel (TWC) reported on the Seahawk fan’s second large recorded earthquake.
TWC Seahawks fans cause another earthquake. http://www.weather.com/news/seahawks-fans-cause-another-earthquake-20140113
The slideshow chart is an archived seismographic summary recorded by Pacific Northwest Seismic Network (PNSN), HWK2 ENZ UW, 2014, 01, 11 (pst). The large seismic event corresponds to the Lynch touchdown (Beastquake 2), including subsequent shocks from replay and extra point. (See slideshow.)
For a more serious look at seismic events and focused low pressure atmospheric weather systems, the Hacklberg EF5 tornado, of April 27, 2011, is such a case. At the scene, Reed Timmer’s Dominator crew and John Halen SWS were documenting the tornado. John stated over a cell phone, “ Reed was saying, do you guys hear that rolling thunder, it doesn't stop? We all said, “Reed that’s not thunder that’s the tornado.” “We could feel it vibrating right through the ground as that monster EF5 approached, it was terrifying to actually feel the ground shake from a tornado so many miles away. At the time, a seismic event was recorded by a university in the region.”
Topic: "seismic event" April 27, 2011 near Hacklesburg, Tuscaloosa and Birmingham, Alabama.
CERI, University of Memphis, operates two seismic networks that include 72 short-period and 12 broadband seismic stations to monitor seismicity in the New Madrid Seismic Zone, and 20 short-period and 5 broadband seismographs in the Southern Appalachian Seismic Zone and recorded seismic events corresponding to an approximate location of the Hacklesberg EF5 tornado track on April 27, 2011.
Mitch Withers, Seismic Network Director, http://www.ceri.memphis.edu/seismic/
At an AMS Severe Local Storms (SLS) conference, Dr. Forbes with the Weather Channel (TWC) recalled early in his forecasting career about predicting one long track violent tornado, that he knew by forecasted conditions the tornado would become violent and deadly. The tornado did in fact become a large deadly wedge that was also recorded by seismograph producing a corresponding 2.1 earthquake. At the AMS SLS conference, Dr. Forbes surmised that particular seismic event resulted from the large tornadoes debris ball with 10s of millions of trees being ripped up and then dropped from high elevations around the core flow path of the progressing violent tornado.
Even oscillating cross winds have enough force to topple a large suspension bridge. The following link is to a video of the Tacoma Narrows bridge collapse.
The Canton Lake tornado of May 24, 2011, had a significant debris ball heading toward Canton Lake, and then produced a displacement wave (photo observations by, principal meteorologist Rutger Boonstra and Tim Marshall) as it crossed the lake, producing a clear eye within the tornado until reaching the other shore, where the tornadoes debris ball again became visible by DOW Doppler scans from both DOW7 and NOXP radars. For more information about the Canton Lake tornado read: "Mobile radar and damage assessment of the May 24th 2011, Canton Lake, Oklahoma tornado," Karen A. Kosiba, Joshua Wurman, Paul Robinson, CSWR, Boulder, Colorado, Christopher Schwarz, OU, Norman, Oklahoma, Donald Burgess, CIMMS, Norman, Oklahoma, Ted Mansell, NSSL, Norman, Oklahoma
Bryan Draper documented the symmetrical (tsunami) waves emanating from the Canton Lake EF4 tornado.
On April 13th, 2013, Lauren and Chris hill were tracking half a dozen evening tornadoes near the Wichita Mountains in Oklahoma, and at one point a large powerful wedge tornado “sounded like continuous rolling thunder” once the team had evacuated the tornadic corridor, and was observing this phenomena several miles outside the wedges path.
On May 20, 2013, Basehunters chasing were documenting the Moore EF5 tornado, and Lauren Hill and Colt Forney indicated the tornado’s waterfall roar was louder than any tornado they’d heard, almost louder than their voices (including sound experienced at close range during the Joplin EF5 tornado), and was almost loud enough to drown out nearby tornado sirens at one point. Lauren and Colt indicated they were periodically blasted by strong oscillating pressure waves from the tornado while they evacuated. There were also powerful tornadoes the day before, on May 19th, 2013, and a 2.9 mag earthquake was recorded northeast of Oklahoma City. However, because of the large number of earthquakes in-and-around the OKC region (some say related to fracking) the occurrence of that single 2.9 mag. quake and the powerful tornado that day may have been coincidental.
Roar of Moore EF5 tornado, Basehunters (May 20, 2013)
The interior core flow region of a tornado is a well understood low pressure zone within the tornado structure. Tim Samaras, Twistex recorded the largest known atmospheric pressure drop (100mb), to date, on June 24, 2003, within an EF4 tornado near Manchester, SD.
Some atmospheric scientists believe there is little correlation between atmospheric conditions and geophysical changes, other than by the effects of erosion due to rainfall volumes. Atmospheric and geophysical scientists agree more remote seismographic sensing of high intensity low pressure severe weather systems is needed to develop confidence in confirming trends that can validate categories or magnitudes of low pressure troughs, or bombogenesis events and likely terrestrial conditions needed to produce significant weather driven earthquakes.
The following are useful links for more information relating to low pressure storm systems and earthquake events.
Could weather trigger earthquakes and landslides?
How storms can trigger earthquakes
Typhoons can trigger slow earthquakes