1998 Pymatuning earthquake

The 1998 Pymatuning earthquake occurred in the U.S. state of Pennsylvania on September 25. With a magnitude of 5.2, it was the greatest recorded earthquake in Pennsylvania's history.

Earthquake

The earthquake's epicenter was at latitude 41°29′24″ N and longitude 80°22′48″ W in the Southern Great Lakes Seismic Zone, about 25 kilometers (16 mi) southwest of Meadville; its depth was 5 kilometers (3 mi). The earthquake caused minor damage in towns near its epicenter and was felt in the states of Ohio, Pennsylvania, Indiana, Michigan, New York, Illinois and New Jersey, as well as Southern Ontario in Canada.^[1]

Hydrologic occurrences

After the earthquake many wells in the epicentral region began to dry up, while new springs and old wells began to flow. A three-month date range revealed 120 dry household-supply wells on the ridge of Jamestown and Greenville.^[2] Declines of up to 100 feet (30 m) were observed on a ridge where at least 80 of these wells resided. The degree of the damage varied. Some of the wells lost all power or could barely hold their yields and some of the water in wells turned black or began to smell of sulfur.

The most likely cause of the wells drying was because of the increase in hydraulic conductivity or "hydraulic islands" of shale rock under this area caused by the earthquake.^[2] The quake affected the existing faults and created new faults in the shale.^[2] This created more permeability for the water to leak down from the hiltops on the ridge down to the valleys following the contours of the Meadville shale down to the 14-18 square km area of the valley.^[2]

References

↑ "Magnitude 5.2 Pennsylvania". United States Geological Survey. November 10, 2003. Archived from the original on 11 March 2009. Retrieved March 20, 2009.
1 2 3 4 Gorokhovich, Y; Fleeger, G (2007). "Pymatuning earthquake in Pennsylvania and Late Minoan Crisis on Crete" (PDF). Water Science and Technology: Water Supply (Vol 1 No 7): 245–251.

← Earthquakes in 1998 →

1st Afghanistan (6.1, Feb 4) † Ryukyu Islands (7.5, May 4) 2nd Afghanistan (6.5, May 30) † ‡ Adana–Ceyhan (6.3, Jun 27) † Azores Islands (6.1, Jul 9) Papua New Guinea (7.0, Jul 17) † Bahía de Caráquez (7.2, Aug 4) Pymatuning (5.2, Sep 25) Mionica (5.5, Sep 29) Ninglang (6.2, Nov 19)

† indicates earthquake resulting in at least 30 deaths ‡ indicates the deadliest earthquake of the year

Earthquakes in the United States

Historical	1638 New Hampshire 1663 Charlevoix 1700 Cascadia 1755 Cape Ann 1811–12 New Madrid 1812 Wrightwood 1838 San Andreas 1857 Fort Tejon 1865 Memphis 1867 Manhattan, Kansas 1868 Hawaii 1868 Hayward 1872 Lone Pine 1872 North Cascades 1886 Charleston 1887 Sonora 1892 Laguna Salada 1892 Vacaville–Winters

20th-century	1906 San Francisco 1906 Aleutian Islands 1909 Wabash River 1915 Pleasant Valley 1916 Irondale 1918 San Jacinto 1925 Santa Barbara 1931 Valentine 1932 Eureka 1933 Long Beach 1935 Helena 1940 El Centro 1940 New Hampshire 1944 Cornwall–Massena 1946 Aleutian Islands 1947 Wisconsin 1948 Desert Hot Springs 1949 Olympia 1952 Kern County 1957 Andreanof Islands 1957 San Francisco 1959 Hebgen Lake 1964 Alaska 1965 Rat Islands 1965 Puget Sound 1968 Illinois 1969 Santa Rosa 1971 San Fernando 1975 Near Islands 1975 Morris 1975 Hawaii 1979 Coyote Lake 1979 Imperial Valley 1980 Eureka 1983 Coalinga 1983 Borah Peak 1984 Morgan Hill 1986 North Palm Springs 1986 Chalfant Valley 1987 Whittier Narrows 1989 Loma Prieta 1990 Upland 1991 Sierra Madre 1992 Cape Mendocino 1992 Landers 1992 Big Bear 1993 Scotts Mills 1993 Klamath Falls 1994 Northridge 1995 Marathon 1996 Duvall 1998 Pymatuning 1999 Hector Mine 2000 Yountville

21st-century	2001 Nisqually 2002 Denali 2003 Alabama 2003 San Simeon 2006 Gulf of Mexico 2006 Hawaii 2007 Alum Rock 2008 Illinois 2008 Chino Hills 2010 Eureka 2010 Illinois 2010 Baja California 2010 Indiana 2011 Colorado 2011 Virginia 2011 Oklahoma 2014 Aleutian Islands 2014 Southeast Alaska 2014 South Napa 2016 Oklahoma

Swarms	2001 Enola 2008 Reno 2010–11 Guy-Greenbrier 2012 Brawley 2009–16 Oklahoma

Coordinates: 41°29′N 80°23′W / 41.49°N 80.38°W / 41.49; -80.38

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