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Site content related to keyword: "earthquakes"

Expert: Earthquake aftershocks could be felt in Delaware in coming days

The outer edge of a 5.9-magnitude earthquake shook the entire eastern seaboard this afternoon, from Delaware as far north as New England, according to multiple reports.

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The science behind earthquakes is not absolute

WBOC news feature involving the earthquake on August 23, 2011 which ocurred in Mineral, Virginia.

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Delaware geological researchers track quake effects, possibility of aftershocks

The Delaware Geological Survey is tracking the possibility of aftershocks as well as still receiving reports from people who felt the effects of Tuesday's earthquake centered in Virginia.

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The Earthquake of August 23, 2011

Seismograph recording of the August 23, 2011 earthquake

Delaware and surrounding areas experienced an earthquake event on the afternoon of Tuesday, August 23, 2011. According to the US Geological Survey, a magnitude 5.8 earthquake struck at 1:51 p.m. in central Virginia, in an area referred to as “the Central Virginia Seismic Zone” because of its relatively active earthquake activity for the region. The epicenter was located five miles south-southwest of Mineral, Virginia, with the quake was focused at a depth of 6 km (3.7 miles) below the surface (http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/se082311a.html). The Virginia Geological Survey reports that this is the largest Virginia earthquake known in historic times. A few small aftershocks have occurred in the hours afterward.

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Stefanie Baxter interviewed by local media regarding earthquake in Japan.

Stefanie Baxter, research associate with the Delaware Geological Survey, was interviewed March 11 by Channel 6 Action News, Channel 16 WBOC and the News Journal, regarding the 8.9 magnitude earthquake in Japan.

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IS5 Earthquakes in Delaware

IS5 Earthquakes in Delaware

Delaware is not in a seismically active region but, even here, earthquakes occur because of sudden adjustments in the earth's crust. Even though such movements can be startling they yield important information about the behavior of the earth and the potential for future events. The Delaware Geological Survey continually monitors seismicity in the State because of both the scientific value of the information and to help address the concern of residents and other agencies over possible effects.

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Chances of large Delmarva quake 'are very remote'

Stefanie Baxter was quoted in an article in the News Journal, and commented on earthquakes in Delaware.

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USGS Real-time Earthquakes Map

Maps and resources for real-time M1+ earthquakes.

DGS Digital Datasets

In the same ways as our printed publications, digital data released by the DGS represent the results of original professional research and as such are used by professionals and the public.

Catalog of Delaware Earthquakes Spreadsheet

Catalog of Delaware Earthquakes Spreadsheet

The occurrences of earthquakes in northern Delaware and adjacent areas of Pennsylvania, Maryland, and New Jersey are well documented by both historical and instrumental records. Over 550 earthquakes have been documented within 150 miles of Delaware since 1677. One of the earliest known events occurred in 1737 and was felt in Philadelphia and surrounding areas. The largest known event in Delaware occurred in the Wilmington area in 1871 with an intensity of VII (Modified Mercalli Scale). The second largest event occurred in the Delaware area in 1973 (magnitude 3.8 and maximum Modified Mercalli Intensity of V-VI). The epicenter for this event was placed in or near the Delaware River. Sixty-nine earthquakes have been documented or suspected in Delaware since 1871.

Investigating the Causes of Earthquakes in Delaware

Presentation on Investigating the Causes of Earthquakes in Delaware

Interactive Map of Delaware Earthquakes

Map and data listing of all earthquakes with an epicenter within the State of Delaware.

Seismic Network Map

The DGS maintains its own network of seismometers to detect local earthquake activity. Following an earthquake swarm in 1972, the DGS established its first seismometer station in Newark. The network now consists of five seismic stations spread across the state: three stations in the Newark-Wilmington area, one at the DEMA office in southern New Castle County, and one at the Sussex County Emergency Operations Center.

Earthquake Felt Report

Please answer every question to the best of your ability. Either fill in the blanks where called for, or check the response that best describes the event. If a question does not apply or if you don't know how to respond to a particular question, simply skip it and go on to the next. Feel free to add additional information in the Additional Comments box at the bottom of the form.

Natural Hazards in Delaware

Hurricane Floyd - 1999

Natural hazards are those events in the physical environment that present risks to human life or property. The DGS identifies and investigates natural hazards to help understand the earth systems that present the hazards and determine strategies to prepare for or mitigate the risks. We are active in advising emergency management agencies on natural hazards, and are included in the Delaware Emergency Operations Plan as an agency having a vital role in dealing with floods, northeaster/extratropical storms, droughts, earthquakes, sinkholes, and dam failures.

OFR11 Effects of Earthquakes and Earth Tides on Water Levels in Selected Wells in the Piedmont of Delaware

OFR11 Effects of Earthquakes and Earth Tides on Water Levels in Selected Wells in the Piedmont of Delaware

Examination of continuous water-level hydrographs from two artesian observation wells in the Piedmont near Newark, Delaware reveals water-level fluctuations caused by earthquakes and by earth tides. The effects of 14 distant earthquakes with MS (surface wave) magnitudes between 6.7 and 8.0 and MB (body wave) magnitudes between 5.9 and 7.0 (National Earthquake Information Service, 1975-1977) have been recorded over a two-year and ten-month period.

OFR43 Results of Trenching Investigations Along the New Castle Railroad Survey-1 Seismic Line, New Castle, Delaware

OFR43 Results of Trenching Investigations Along the New Castle Railroad Survey-1 Seismic Line, New Castle, Delaware

Five trenches were excavated to a depth of 5 to 8 ft along the path of an abandoned railroad grade near the city of New Castle to investigate potential near-surface faults that may be related to earthquake activity in northern Delaware. Seismic reflection profiles along this line suggested the existence of significant faulting in the area, which lies along a postulated fault trend in eastern New Castle County. Subsequent drilling, however, failed to substantiate displacement interpreted for faults in the sedimentary section. Detailed examination of exposures in the trenches also failed to reveal the existence of near surface faults. Together these findings suggest that there has been minimal or no modern near-surface fault activity in this area of New Castle County.

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OFR42 Catalog of Earthquakes in Delaware

OFR42 Catalog of Earthquakes in Delaware

The occurrences of earthquakes in northern Delaware and adjacent areas of Pennsylvania, Maryland, and New Jersey are well documented by both historical and instrumental records. Over 550 earthquakes have been documented within 150 miles of Delaware since 1677. One of the earliest known events occurred in 1737 and was felt in Philadelphia and surrounding areas. The largest known event in Delaware occurred in the Wilmington area in 1871 with an intensity of VII (Modified Mercalli Scale). The second largest event occurred in the Delaware area in 1973 (magnitude 3.8 and maximum Modified Mercalli Intensity of V-VI). The epicenter for this event was placed in or near the Delaware River. Sixty-nine earthquakes have been documented or suspected in Delaware since 1871.

OFR4 Papers Presented by Staff Members of the Delaware Geological Survey at the Baltimore Meeting of the Northeastern Section of the Geological Society of America, March, 1974

OFR4 Papers Presented by Staff Members of the Delaware Geological Survey at the Baltimore Meeting of the Northeastern Section of the Geological Society of America, March, 1974

This report is a compilation of four papers presented by DGS staff members at the Baltimore Meeting of the Northeastern Section of the Geological Society of America, March, 1974.