The U.S. Geological Survey has posted this map of the 5.9-magnitude earthquake that hit central Virginia just before 2 p.m. today, sending tremors up and down the East Coast.
The yellow glow represents the area where potential damage is deemed "light" and perceived shaking is "moderate."
The quake’s frequency hit the geology of the region just right, like a tuning fork, and reverberated outward, said Alexander Gates, the chairman of earth and environmental sciences at Rutgers-Newark, and an earthquake expert. But there’s no likely danger for aftershocks of the Virginia quake, which will be significantly more minor, he said.
“That was pretty good, huh? I was impressed,” Gates said. “You don’t get earthquakes like that so often on the East Coast.”
Though small earthquakes occur in New Jersey all the time, earthquake experts said today's shaking was highly unusual.
"It's probably the largest one people have felt in New Jersey in decades," said Martha Withjack, professor of geological sciences at Rutgers University in New Brunswick.
The Virginia-centered earthquake was felt all along the East Coast because of the nature of the area's rocks, Withjack said. Unlike the West Coast, where the underlying rocks are broken from frequent quakes, the older rocks beneath New Jersey are long and solid. That means the shaking in Virginia was easily transferred to New Jersey.
"The energy all the way from Virginia got transferred to us," Withjack said.
The magnitude of the earthquake was a 5.9, according to the USGS.
The USGS is also expected to release official intensity numbers, which use a different scale to document how intensely the shaking was at various points along the East Coast. The intensity scale goes from 1 to 12, with 12 being the highest. It is likely New Jersey was at a 3, which is considered the low end of the scale with no damage, Withjack said.
"California wouldn't even blink about this," Withjack said.
According to the scale, an intensity of 3 is described as: "Felt quite noticeably by people indoors, especially on the upper floors of buildings. Many do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibration similar to the passing of a truck. Duration estimated."
There is a chance this earthquake was a precursor to a larger quake that will happen within a few days. But the chances are very small.
"It's not likely," Withjack said.
