Is a 4.8 earthquake possible? Why rare earthquakes may be becoming more common – NBC New York

Residents of New Jersey and New York were jolted Friday morning by an escalating, rumbling tremor. It was the second time this year that an earthquake has struck the region, prompting panicked calls from Manhattan to Albany to Long Island, Montclair and Brooklyn.

An earthquake is usually a foreign experience to New Yorkers, and it naturally raised the alarm with minds rushing to the worst possible conclusions. However, it was just nature taking its course and experts say residents may need to be more prepared for the future.

The Northeast region has experienced more than 2,000 recorded earthquakes since the 1700s, according to National Earthquake Information Center. The one in New Jersey on Friday was a magnitude 4.8 and did not cause much damage. So far, there have only been 13 earthquakes in the region that have been deemed “damaging” by the center.

New York felt another earthquake earlier this year. The United States Geological Survey (USGS) reported a magnitude 1.7 earthquake near Astoria, Queens in January.

Earthquakes are the result of pressure released in the form of seismic waves from fault lines or fractures in the Earth's crust. Fault lines are caused by the sliding of the planet's outer shell, or tectonic plates, which are always moving, but from time to time, are pushed and rubbed together resulting in the release of energy or an earthquake.

Earthquakes have no seasonality and can occur at any time, but mornings and evenings are more likely to see a strike, according to the USGS.

Janti Soeripto, president of Save the Children, was speaking at the United Nations Security Council on humanitarian aid in Gaza before the 4.7-magnitude earthquake struck on Friday morning.

Dr. Antonios Marcellos, an associate professor in the Department of Geology, Environment and Sustainability at Hofstra University, explained that even though New York sits on a certain type of plate, earthquakes do happen.

“An earthquake is based on tectonic plates, and New York sits on a 'lazy' plate, which is good, meaning we don't get as many earthquakes, but there are other things that happen — a lot of rain or drought.” Dr. Marcellos told NBC New York.

Long periods of flooding can cause water levels to rise leading to possible landslides. These slides can “lubricate” faults and may be responsible for a higher frequency of earthquakes, Dr Marcellos explained.

The truth is that this phenomenon happens all the time all over the world. The National Earthquake Information Center detects about 20,000 earthquakes internationally each year and about 55 per day.

“The planet we live on is constantly moving, albeit very slowly. The Earth has a large mantle that is connected all the way from the surface down to the liquid iron core, and this transport leads to movements at the surface that lead to earthquakes wherever the rocks are brittle enough,” explained Jeffrey Park, a professor of Earth and Planetary Sciences at Yale University, behind these occurrences.

Large earthquakes occur on fault zones, or areas of cracks in the Earth's crust, where rock will break. The most dangerous fault areas are on the West Coast, including California and Washington state.

Dr. Park said that continued sea-level rise may increase the stress on Earth's shelves and coastlines, resulting in mostly scattered and infrequent earthquakes with long lead times.

On the plus side, experts say there is no cause for concern and no major earthquake is expected anytime soon.

“I wouldn't worry too much about it. The East Coast has been geologically stable for millions of years,” said Dr. Stephen Holler, an associate professor of physics at Fordham University.

The USGS reports that there are 16 major earthquakes each year with a magnitude between 7 and 8 on the Richter scale. Government agency records show over the past five decades that the long-term average number of major earthquakes has exceeded about a dozen times.