2.2 magnitude earthquake recorded in near Califon, marking 6th quake this month

CALIFON, New Jersey (WPVI) -- A 2.2 magnitude earthquake rattled part of New Jersey on Wednesday.

The earthquake was recorded about 3.1 miles east of Califon, Hunterdon County at about 1:44 a.m., according to the U.S. Geological Survey.

This is the sixth earthquake recorded this month in New Jersey. Five of the six have been near Califon, while a 2.0 magnitude tremor was recorded near New Egypt in Ocean County on July 6.

Jersey has been feeling tremors -- or aftershocks -- ever since a 4.8 magnitude earthquake shook the Northeast in April. That quake, which hit in Hunterdon County, New Jersey, is the strongest on record in the area -- at least going back to when USGS data began in 1957. It was centered between the towns of Whitehouse Station, Califon and Lebanon. That area is about 60 miles northeast of Philadelphia. It had a depth of about 3 miles, the U.S. Geological Survey said.

Aftershocks are smaller earthquakes that occur in the same general area during the days to years following a larger event or "mainshock," according to USGS. The frequency of the aftershocks are expected to decrease with time.

There have been at least 100 tremors around Hunterdon County since the April earthquake.

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