|
|
|
North Idaho celebrates Earth Day with
earthquakes |
|
April 27, 2015 |
April 24, 2015
To the Editor:
At approximately 7:32 p.m. Thursday, April 23,
2015, I was sitting on my couch watching
television when I noticed my four dachshunds
awaken beside me and appeared to be startled.
Just as they started to bark, I heard a rising
amplitude grinding, dragging sound followed by a
high-frequency vibration within my house. I
could hear dishware rattling within my cabinets,
and pictures were rattling on the walls. This
lasted for about eight seconds.
Having experienced several earthquakes before
ranging from 2 to 7 on the Richter scale, I knew
immediately what was happening. I called a few
of my neighbors; some felt it, some did not.
The U.S. Geological Survey reported this quake
at magnitude 4.1 at a depth of just over 3 miles
with the epicenter located approximately 15
miles southeast of Sandpoint at a location under
Lake Pend O'Reille near Farragut State
Park/Bottle Bay. As far as earthquakes go, this
is rather shallow and resulted in the very
noticeable seismic activity given the magnitude.
At approximately 10:45 p.m., a second earthquake
hit. This temblor arrived with a very different
low-frequency rumbling, roaring sound followed
by upward, downward, and sideways motions within
my house. This shaking motion lasted a bit
longer than the first one and seemed
significantly stronger. I noticed my walls
appearing to sway. My dogs were acting gun shy
at this point.
The U.S.G.S. reported this quake at a magnitude
of 4.2, and the epicenter was further north this
time, but still underneath Lake Pend O'Reille at
a location between Hope and the Forrest Bird
Aviation Museum. This quake was more widely-felt
than the first one by residents here in Bonners
Ferry/Boundary County.
I gave a telephone interview during KHQ-TV's
(NBC;Spokane, Washington) 11:00 p.m. news live
broadcast, giving my account of last evening's
experience. Shortly thereafter, I retired for
the night.
At approximately 1:28 a.m., I was awakened by a
third temblor which the U.S.G.S. reported at a
magnitude of 3.3 with the epicenter near the
same location as the second one. I probably
would have slept through this one had I not been
hypervigilant from the first two.
Yesterday, a 2.8 magnitude earthquake was
reported as well in Council, Idaho, located
north of Boise. This morning at 6:56 a.m., a
magnitude 6.2 earthquake was reported at the
southern tip of Queen Charlotte Island located
off of the west coast of British Columbia.
This "swarm" of seismic events appears related
to the subduction of the Pacific plate
underneath the North American plate. This
activity results in an upward thrust of the
North American plate. Some seismologists have
predicted a massive 8.0 or greater magnitude
earthquake to occur along the Cascade fault
region within the next 30 years.
Seismic and/or volcanic activity are the way
nature relieves the stresses built up by
movement of tectonic plates. Recently,
Kalispell, Montana experienced a minor
earthquake and there have been several accounts
given about the potential of the supervolcano
that rests beneath Yellowstone National Park.
I do not think there is cause for alarm at this
time, but we might be in for an interesting
period.
Gerald Higgs |
|
|
|
Questions or comments about this
letter?
Click here to e-mail! |
|
|
|
|
