New England Seismic Network News

August 25, 2011

Virginia Aftershocks – August 25, 2011

Filed under: Uncategorized — NESN @ 1:00 pm

Aftershocks of the August 23rd Virginia magnitude 5.8 earthquake continue, and are being recorded by Weston Observatory’s New England Seismic Network as well as the Virginia Tech Seismological Observatory.

Below is a seismogram of Virginia aftershocks recorded on Virginia Tech’s seismograph in Lynchburg, VA:

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Magnitude 4.5 – VIRGINIA Aftershock – August 25, 2011

Filed under: Uncategorized — NESN @ 1:52 am

Weston Observatory seismographs recorded the magnitude 4.5 aftershock from Mineral, Virginia on August 25, 2011.

For more info on these earthquakes, go to US Geological Survey report.

Seismogram of aftershock recorded on Weston Observatory seismograph:

August 24, 2011

Magnitude 4.2 and Magnitude 3.4 – VIRGINIA AFTERSHOCKS

Filed under: Uncategorized — NESN @ 1:02 pm

Weston Observatory seismographs recorded the magnitude 4.2 and magnitude 3.4 aftershocks from Mineral, Virginia on August 24, 2011.

For more info on these earthquakes, go to US Geological Survey report.

Seismogram of aftershocks recorded on Weston Observatory seismograph:

August 23, 2011

Magnitude 5.8 – Virginia – August 23, 2011

Filed under: Uncategorized — NESN @ 3:20 pm

Weston Observatory seismographs recorded the magnitude 5.8 earthquake 14 km (9 miles) SSW from Mineral, Virginia on August 23, 2011.
LATITUDE 37.881°N,    LONGITUDE  -77.952°W
For more info on this earthquake, go to US Geological Survey report.

Earthquakes in Virginia and Vicinity 1774 – 2004
By Arthur C. Tarr and Russell L. Wheeler

This quake was felt throughout New England.
For an Intensity Map of the felt area and/or if you felt this quake, please report it with USGS Did You Feel It? – Tell Us!

For a news report, click CNN.com

Seismogram of quake recorded on Weston Observatory seismograph:

April 7, 2011

Magnitude 7.1 – NEAR THE EAST COAST OF HONSHU, JAPAN – April 7, 2011

Filed under: Uncategorized — NESN @ 11:56 am

Weston Observatory seismographs recorded the magnitude 7.1 aftershock NEAR THE EAST COAST OF HONSHU, JAPAN on April 7, 2011.
LATITUDE 38.253°N, LONGITUDE 141.640°E
For more info on this earthquake, go to US Geological Survey report.

For a news report, click CNN.com
There were no immediate reports of casualties or damage, however the Fukushima Daiichi nuclear plant has been evacuated. –CNN.com

March 29, 2011

Are we in a period of increased earthquake activity ?

Seismologists normally expect, on average, one magnitude 8 earthquake to occur per year, somewhere in the world, and, again on average, just one magnitude 9 earthquake per decade. While these numbers are just expectations of averages, the recent Japan earthquake (Mw 9.0), following just 7 years after the 2004 Mw 9.1 Sumatra earthquake, and just 1 year after the 2010 Mw 8.8 Maule, Chile earthquake, raises the question: Are we in a period of increased global earthquake activity ?

To answer this question, I produced a spreadsheet using the largest (Mw >= 8.5) earthquakes in the world since 1900 (which is around when we began recording earthquakes instrumentally so that we can accurately measure earthquake magnitudes).

When you go to clean up your computer disk, you probably start by arranging the files in order of decreasing size, with the largest files at the top. You do this because it’s much more efficient to remove a single, large file, then to track down and remove many small files. In the same way, a single large earthquake (e.g., Mw >= 8.5) releases much more energy than all of the smaller earthquakes put together, and accounts for most of the seismic energy release within a given time period.

Table 1. Largest earthquakes (Mw >= 8.5) in the world since 1900, arranged chronologically and converted to energy.

Mw_Energy_Released_Since_1900

March 11, 2011

Magnitude 9.0 – NEAR THE EAST COAST OF HONSHU, JAPAN – March 11, 2011

Filed under: Uncategorized — NESN @ 9:00 am

The NESN recorded the devastating magnitude 9.0 earthquake near the East coast of Honshu, Japan on March 11, 2011.  This is the largest recorded earthquake in Japan and the 5th largest earthquake recorded in the World.
Fires broke out at oil refineries, firefighters continue to battle a large fire at Cosmo Oil Co.’s refinery, 40 kilometers east of Tokyo.  Millions of homes are without electricity as utilities shut 11 nuclear power reactors.
For News:  CNN, Bloomberg

LATITUDE  38.322°N,  LONGITUDE  142.369°E
For more info on this earthquake, go to US Geological Survey report.
For a list of aftershocks of magnitude 5.0 and larger, go to Latest USGS Earthquakes.
For a tectonic summary, go to USGS Tectonic Summary.

A power point on the tectonics and details of this devastating earthquake and tsunami can be downloaded from the IRIS website here.
To download a PDF of this IRIS presentation, click here.

A tsunami was generated by this enormous quake and traveled miles inland Japan sending a massive body of water filled with debris that included cars, boats and houses.
The western Aleutian Islands, Alaska, were hit at 4 a.m. EST by a 5.1 foot wave.  Shemya, Alaska was reporting no damage despite the sizeable wave. By the time it reached the commercial fishing town of Dutch Harbor, the wave was just 1.6 feet.
For more tsunami info visit the Pacific Tsunami Warning Center.
For an animation of how the D.A.R.T. II deep ocean system works in assessing and reporting a tsunami, click here.


January 3, 2011

Magnitude 2.5 – NEW HAMPSHIRE – January 2, 2011

Filed under: Uncategorized — NESN @ 3:23 pm

A magnitude 2.5 earthquake occurred at 11:46PM local time, and was located 6 miles ENE of Plymouth, NH.
The earthquake was felt throughout central New Hampshire.

If you felt this earthquake please report it here.
For more info on this earthquake, go to:
New England Seismic Network News
US Geological Survey report

For details on the Seismology, Geology, Faulting, and Historic Seismicity of Central New Hampshire,
view the Tectonic Summary.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


January 2, 2011 New Hampshire M 2.5 earthquake as recorded by New England Seismic Network (NESN) station WES (Weston, MA).

September 26, 2010

Magnitude 3.1 – NW OF CONCORD, NEW HAMPSHIRE – September 25, 2010

Filed under: Uncategorized — NESN @ 12:08 pm

A magnitude 3.1 earthquake occurred at 11:28PM local time and was located 8 miles NW of Concord, NH. The earthquake was widely felt throughout southern and central NH.

If you felt this earthquake please report it here

September 25, 2010 New Hampshire earthquake Did you Feel It Map

USGS Did You Feel It Map as of 12 noon on Sunday September 26, 2010.

September 25, 2010 New Hampshire M 3.1 earthquake as recorded by New England Seismic Network (NESN) stations

July 26, 2010

Magnitude 3.1 – OFFSHORE MAINE – July 25, 2010

Filed under: Uncategorized — NESN @ 1:15 pm

The New England Seismic Network recorded a magnitude 3.1 earthquake offshore Maine, 43KM SSE OF EASTPORT, on June 25, 2010.  This earthquake was felt along the coasts of New Brunswick and Nova Scotia.

If you felt this earthquake please report it here.

For more info on this earthquake, go to US Geological Survey report.

Seismogram recorded at EMMW:


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