The southern Italian city of Naples was struck by a 4.4-magnitude quake early Thursday that caused only minor damage

An earthquake is caused when two blocks of Earth's crust slip past each other on a fault plane, according to the U.S. Geological Survey.

An active volcano near Alaska's most populated city could be on the brink of eruption, according to scientists who are constantly monitoring a potential threat.

An eruption could impact the most populated city in Alaska.

Preliminary figures measured a 7.6 magnitude earthquake, as a tsunami advisory is in effect for the Caymans and Puerto Rico.

A 3.8 magnitude earthquake rattled the region early Monday, with trembles felt in Portsmouth, New Hampshire, and an hour away in Boston. The quake was centered 10 km southeast of York Harbor, Maine.

A 3.9 magnitude earthquake struck off the coast of New England Monday morning.

The U.S. Geological Survey put the quake’s preliminary magnitude at 6.8.

Chinese media also reported that as of 10 a.m. local time, multiple aftershocks were recorded, the largest of which was 4.4.

At least 126 people were killed and more than 100 others were injured after the powerful earthquake struck around 45 miles north of Mount Everest along the border with Nepal.

ABC News’ Britt Clennett reports on the earthquake that has injured more than 188 people, according to Chinese state media.

The embassy "sustained considerable damage during the earthquake and is closed until further notice," U.S. officials said in a statement.

CCTV video shows homes and businesses shaking as a 7.3 magnitude earthquake rocked the Pacific island of Vanuatu, causing widespread damage.

A 7.0 magnitude earthquake rocked Northern California on Thursday, leading to a brief tsunami warning for coastal areas in California and Oregon.

A 7.0 magnitude earthquake was reported in northern California on Thursday, according to the United States Geological Survey.

Seismologist Dr. Lucy Jones discussed the 7.0 earthquake that hit off the coast of Northern California on Thursday.

William Barnhart, assistant coordinator at USGS Earthquake Hazards Program, discussed the 7.0 magnitude earthquake near Northern California on Thursday.

The epicenter is near Petrolia, in Humboldt County, the United States Geological Survey (USGS) said.

A tsunami warning is in effect after a 7.0-magnitude earthquake was reported in Northern California.

A 4.7 magnitude earthquake centered in Malibu, California, rocked the Los Angeles area Thursday morning.

A 4.7 magnitude earthquake centered near Malibu rocked the Los Angeles area early Thursday in what experts say has been a record-breaking year for seismic activity.

A 4.7 magnitude earthquake centered in Malibu, California, rocked the Los Angeles area Thursday morning.

Millions in Los Angeles are on alert for potential aftershocks after the earthquake rattled Southern California.

A 4.4 magnitude earthquake rocked the Los Angeles region early Monday afternoon.

The epicenter was near the city's Highland Park neighborhood.

A 4.4 magnitude earthquake rocked the Los Angeles region early Monday afternoon.

A local radio station's office could be seen vigorously shaking in footage captured during a strong earthquake that rocked the coast of southern Japan on Thursday.

A strong earthquake with a preliminary magnitude of 7.1 has rocked the coast of southern Japan.

California experienced a spate of earthquakes on Tuesday night.

The Texas Railroad Commission, which regulates oil production in the state, is investigating whether recent earthquakes are being caused by fracking.

Scurry County Judge Dan Hicks declared a disaster and urgently requested state assistance on Friday after the 61st earthquake in the past seven days.

Researchers will use a PetPace wearable health tracker to measure dogs’ physiological responses leading up to an earthquake.

A device that dogs wear on their collar could finally make use of thousands of years of anecdotes detailing a change in behavior in animals before an earthquake.

The magnitude 4.1 earthquake centered near Corona, in Riverside County.

More than 30 aftershocks have happened since the rare 4.8 magnitude earthquake on Friday that was felt as far south as Washington, D.C., and up to Maine.

The surprise quake is the strongest to hit the region in nearly 140 years.

Earthquakes along the Atlantic Seaboard are "uncommon but not unheard of," according to the U.S. Geological Survey.

A 4.8 magnitude earthquake rocked the Northeast Friday morning, shaking buildings from New Jersey to New York City and Connecticut.

Experts warn that possible aftershocks following the tremors can continue for days.

A look at the numbers behind the magnitude of earthquakes that have rocked the world as a 4.8 magnitude earthquake recorded on the East Coast became the strongest earthquake in the area since 1884.

The 4.8 magnitude earthquake that surprised the Northeast was centered in New Jersey and shook from Washington, D.C. up to Maine. ABCs Victor Oquendo speaks to Dr. Angie Lux about the rare occurrence.

A 4.8 magnitude earthquake hit the Northeast Friday morning, shaking buildings in several states, including New Jersey, New York and Connecticut.

Lucy Jones, seismologist and founder of Dr. Lucy Jones Center for Science and Society joins ABC News Live to discuss.

Tremors from the quake were felt from Washington, D.C. to New England

While it may be hard to predict when an earthquake will strike, emergency management experts say there are steps that anyone can take to stay safe.

A 4.8 magnitude earthquake rocked the Northeast Friday morning.

A 4.7 magnitude earthquake was felt across the Northeast on Friday morning.

Residents react to an earthquake that hit New Jersey on Friday. It could be felt in New York City and as far as Washington, D.C., and Maine.

The earthquake was centered near Whitehouse Station, New Jersey, and could be felt as far south as Washington, D.C., and as far north as Maine.

UCLA professor of engineering John Wallace compares the readiness of West and East Coast cities.