Why am I'm up so early this morning? This would explain why:

Yes, that would be a shake-map from the USGS. My sister called me at 5:00am this morning, telling me the shaking was so violent that it woke her up in Fishers, IN. Just from looking around at helicorders around the Midwest and Ohio Valley, this thing was felt across a fairly widespread area. Like I explained to my sister, there's a lot of solid ground in that part of the country and many, many shallow faults across the region. Preliminary reports are that this was a 5.4 on the Richter Scale. Quite strong for this part of the country!

Here are a couple of the helicorders I've looked at the past half-hour or so that are located near the epicenter.





This one, located near Olney, IL was likely the closest to the epicenter of the earthquake. As you can see, the quake, itself, lasted for a good 5-8 minutes (probably only about 5 minutes of shaking would have been felt, maybe even less, depending how shallow it occurred). Also, you may note several very small aftershocks after the main quake. You can see them on the traces, at the very end of the 4:45am trace and several others along the 5:00, 5:15, and 5:30am traces.





This one, located in Bloomington, IN doesn't show the quake lasting nearly as long and much less activity as far as aftershocks were concerned. A very weak one appears around 5:37am. The intensity here probably wasn't all much less than that near Olney. Obviously, P-waves (the deep, short wave-length, high amplitude waves that travel through Earth's crust) dampen with distance, but limestone is much more prevalent in southern Indiana, so the waves likely didn't dampen as much as you'd think. Bloomington isn't even maybe 50-70 miles away from the epicenter, so that's, obviously, a factor. The other type, by the way, S-waves (surface-waves) occur much shallower and on a longer wave-length.

Either way, a 5.4 quake along the IL/IN border is a fairly significant event. Likely nothing that would result in any major damage, but surely felt. As evidenced here. I even checked out some Helicorders around the upper Midwest - some in Minnesota that even picked up on the quake. Goes to show how far P and S-waves can travel!

Edit (6:30am CDT): It appears that the USGS has confirmed it as a 5.2 quake and a fairly shallow one, as I expected.

For more information...

A fairly potent low-pressure system pushed northeast across the Ohio Valley Thursday, December 8th, resulting in sigificant snowfall amounts across much of Indiana. Amounts ranged from 1-4 inches across the far south to over 8 inches over parts of the northeast. While my hometown of Bluffton didn't have any official measurements through the Northern Indiana National Weather Service, surrounding reports ranged from 8 inches in Huntington to 9.2 inches in Ossian.

Here are various reports across southern Michigan, northern Indiana, and northwestern Ohio; as distributed by the Northern Indiana NWS office this afternoon:

PUBLIC INFORMATION STATEMENT...UPDATED
NATIONAL WEATHER SERVICE NORTHERN INDIANA
350 PM EST FRI DEC 9 2005

A LOW PRESSURE SYSTEM MOVED ACROSS THE MIDWEST THURSDAY AFTERNOON
AND THURSDAY NIGHT CAUSING HEAVY SNOW OVER THE AREA. HERE ARE THE
MOST RECENT STORM TOTAL SNOWFALL AMOUNTS.


LOCATION             COUNTY         SNOWFALL TOTAL


...SOUTHWEST LOWER MICHIGAN...

ST. JOSEPH           BERRIEN              9.0
NILES                BERRIEN              8.6
BUCHANAN             BERRIEN              8.0
BENTON HARBOR        BERRIEN              6.9
2S BENTON HARBOR     BERRIEN              6.8
CASSOPOLIS           CASS                 8.5
SISTER LAKES         CASS                 8.1
UNION                CASS                 6.0
BRONSON              BRANCH               9.2
QUINCY               BRANCH               7.5
WHITE PIGEON         ST. JOSEPH           8.0
STURGIS              ST. JOSEPH           8.0
THREE RIVERS         ST. JOSEPH           7.0
6S HILLSDALE         HILLSDALE            7.5
HILLSDALE            HILLSDALE            7.0
LITCHFIELD           HILLSDALE            6.4


...NORTHERN INDIANA...

NWS NORTHERN INDIANA KOSCIUSKO            9.4
2SW NORTH WEBSTER    KOSCIUSKO            9.3
SYRACUSE             KOSCIUSKO            7.1
3SE WARSAW           KOSCIUSKO            7.0
1E WINONA LAKE       KOSCIUSKO            6.6
MENTONE              KOSCIUSKO            6.0
FISH LAKE            LAPORTE              9.0
LA PORTE             LAPORTE              7.5
OTIS                 LAPORTE              7.0
MICHIGAN CITY        LAPORTE              6.5
LAPORTE WWTP         LAPORTE              6.1
KINGSBURY            LAPORTE              5.0
SOUTH BEND AIRPORT   ST. JOSEPH           8.2
SIMONTON LAKE        ELKHART              9.5
2E ELKHART           ELKHART              9.5
GOSHEN               ELKHART              9.0
WAKARUSA             ELKHART              8.0
ELKHART              ELKHART              7.5
2N MILLERSBURG       ELKHART              7.2
MILLERSBURG          ELKHART              7.0
NAPPANEE             ELKHART              7.0
MIDDLEBURY           ELKHART              6.0
ROCHESTER            FULTON               7.9
METZ                 STEUBEN             10.0
ANGOLA               STEUBEN              8.5
SALEM CENTER         STEUBEN              8.0
4N ANGOLA            STEUBEN              7.5
2E SALEM CENTER      STEUBEN              5.5
5NE FORT WAYNE       ALLEN               10.0
5N FORT WAYNE        ALLEN                8.7
FORT WAYNE AIRPORT   ALLEN                8.4
5N FORT WAYNE        ALLEN                8.0
2NW FORT WAYNE       ALLEN                8.0
MONROEVILLE          ALLEN                6.0
NORTH JUDSON         STARKE               6.0
1.5S ALDINE          STARKE               4.5
7N COLUMBIA CITY     WHITLEY              9.0
COLUMBIA CITY        WHITLEY              8.5
COESSE               WHITLEY              7.0
MEXICO               MIAMI                9.0
LOGANSPORT           CASS                 8.0
GALVESTON            CASS                 7.0
ROYAL CENTER         CASS                 7.0
YOUNG AMERICA        CASS                 6.0
PLYMOUTH             MARSHALL             7.2
BREMEN               MARSHALL             7.0
CHALMERS 5W          WHITE                7.0
HEADLEE              WHITE                7.0
MARION               GRANT                6.5
HUNTINGTON           HUNTINGTON           8.0
WINIMAC              PULASKI              6.0
HARTFORD CITY        BLACKFORD            6.1
WATERLOO             DEKALB               8.0
AUBURN               DEKALB               7.8
3SW ASHLEY           DEKALB               6.8
KENDALLVILLE         NOBLE                7.0
CROMWELL             NOBLE                6.5
OSSIAN               WELLS                9.2
LAGRANGE             LAGRANGE             9.0
WABASH               WABASH               8.0
DECATUR              ADAMS                7.0
PORTLAND             JAY                  7.0


...NORTHWEST OHIO...

OTTAWA               PUTNAM               8.0
COLUMBUS GROVE       PUTNAM               6.1
PANDORA              PUTNAM               5.5
VAN WERT             VAN WERT             7.5
SPENCERVILLE         ALLEN                6.0
LIMA                 ALLEN                5.0
GOMER                ALLEN                4.0
MONTPELIER           WILLIAMS             7.3
DEFIANCE             DEFIANCE             8.0
WAUSEON              FULTON               8.0
NAPOLEON             HENRY                8.0
PAULDING             PAULDING             8.0