The massive, magnitude-8.3 temblor that struck today (May 24) near Russia's Kamchatka Peninsula could turn out be the deepest earthquake ever recorded.

At 378 miles (609 kilometers) below the seafloor, the quake could best the previous record set in Bolivia, in 1994. The initial depth may be revised as scientists collect more data. The Bolivian quake was a magnitude-8.2, and 392 miles deep (631 km), Nature News reported.

Why so deep? The Sea of Okhotsk sits above a subduction zone, where the Pacific Plate dives beneath the North America Plate. (Though some scientists think there is also a microplate, a small tectonic plate, beneath the sea.) The northwest Pacific crust is some of oldest, coldest oceanic crust subducting on Earth. It's also quickly rolling into the subduction zone, like a speedy conveyor belt, so the cold crust reaches deep into Earth's mantle before warming up.

Event Time
2013-05-24 14:56:31 UTC
2013-05-25 00:56:31 UTC+10:00 at epicenter

Location
52.222°N 151.515°E depth=623.0km (387.1mi)

Nearby Cities
353km (219mi) WNW of Ozernovskiy, Russia
473km (294mi) W of Vilyuchinsk, Russia
476km (296mi) W of Yelizovo, Russia
491km (305mi) W of Petropavlovsk-Kamchatskiy, Russia
2061km (1281mi) NNE of Tokyo, Japan
Technical Details

At least 22 aftershocks have struck following an earthquake in far northeastern California that was felt as far away as San Francisco and in two other states.

There have been no reports of injury or serious damage.

Officials said the magnitude-5.7 quake broke dishes and shook mirrors when it hit at 8:47 p.m. Thursday.

The U.S. Geological Survey's National Earthquake Center said it was centered near Greenville, about 25 miles southwest of Susanville. It was followed by multiple aftershocks, including a magnitude 4.9 temblor that struck early Friday morning.

Pacific Gas & Electric said about 660 customers lost power on the southwestern edge of Lake Almanor at about 9:39 p.m. Thursday. The company did not immediately clarify whether the outage was due to the quake.

The remote volcano in the northern Kuriles is probably in eruption, the latest SVERT report and satellite images suggest. A plume of gas and steam, and possibly some minor amounts ash was seen with the MODIS sensor onboard the NASA Terra satellite this morning. Satellite data also indicate that activity had likely already started in early May, because a small thermal anomaly can be traced back on archive pictures to 7 May. One should take into account that frequent dense cloud cover often prevents such observations, so activity could have started earlier than that. It is not known what kind of activity is occurring at the volcano. Possibilities include some minor explosive (strombolian ?) activity at the summit, or lava flows that might be reaching the sea and produce the steam plume observed. The last eruption of the volcano was (probably) in 2004. - Volcano Discovery

SERNAGEOMIN has raised the alert level to orange. Since May 15, a progressive increase in seismic activity as well emissions of gas and now some ash have been observed. Both earthquakes related to rock fracturing and fluid movements have picked up in numbers and possibly indicate a new magmatic intrusion on its way. This scenario is confirmed by the start of small ash emissions and glow at the crater which is visible at night. The plume of gas and ash could be seen from space by the MODIS sensor, stretching about 100 km to the southeast. Copahue volcano had already experienced a first increase of activity in December, and a second one in January. No eruption followed and alert was lowered to green in April before returning to yellow again soon after. - Volcano Discovery

The 2013 Atlantic hurricane season, which begins June 1, is shaping up to deliver above-normal activity again this year, according to several seasonal forecasts. Indeed, the season could be extremely active, according to Kathryn Sullivan, acting administrator of the National Oceanic and Atmospheric Administration (NOAA).

Forecasters at the agency's Climate Prediction Center anticipate from 13 to 20 tropical storms over the six-month season. Of those, between seven and 11 are expected to become hurricanes, with three to six of the hurricanes expected to reach "major" status, meaning they host maximum sustained winds topping 111 miles an hour.

The federal forecast, released Thursday afternoon, brackets other seasonal outlooks that also point to a busy season.

In April, for instance, researchers at Colorado State University in Fort Collins released their initial forecast for 2013, which included 18 tropical storms, of which nine are expected to become hurricanes. Four could become major hurricanes.

Tremors have been felt all across Russia and in Europe, following a major 8.2 earthquake in the Sakhalin region

Panicking Muscovites began calling security services, and some decided to leave their homes.

The residents informed security services of vibration and tremors that caused furniture and kitchen utensils to move.

The magnitude of the tremors felt in Moscow was no higher than 1 on the Richter scale, the Agency of Hydrometeorological and Environmental monitoring indicated.

More than a dozen aftershocks were reported Thursday night following a 5.7 earthquake about 150 miles northeast of Sacramento, officials said.

The initial quake hit about 8:47 p.m.; its epicenter was about 27 miles southwest of Susanville and seven miles west northwest of Greenville, according to the U.S. Geological Survey.

People on Twitter told The Times they felt that quake in Sacramento and Lodi, as well as South Reno and on the northwest shore of Lake Tahoe.

Police officials in Susanville and Sacramento said that the quake set off a number of home and car alarms and rattled windows but that there were no immediate reports of damage.

"We got a bunch of alarm calls and a bunch of barking dogs," dispatcher Taylor Richards of the Sacramento Police Department told The Times. "It was a good solid feel here."

Within minutes of the quake, more than 7,000 people reported feeling it on the USGS website.A man in Chico told The Times he felt a slow roll that lasted about 30 seconds.The aftershocks' magnitude ranged up to 3.5, according to the U.S. Geological Survey.

"House shook pretty hard," one man near Truckee told The Times.

Event Time
2013-05-24 05:44:49 UTC
2013-05-24 15:44:49 UTC+10:00 at epicenter


Location
54.870°N 153.334°E depth=601.8km (373.9mi)

Nearby Cities
359km (223mi) WSW of Esso, Russia
379km (235mi) WNW of Yelizovo, Russia
396km (246mi) NW of Vilyuchinsk, Russia
403km (250mi) WNW of Petropavlovsk-Kamchatskiy, Russia
2375km (1476mi) NNE of Tokyo, Japan

Technical Details

Event Time
2013-05-23 21:07:40 UTC
2013-05-23 09:07:40 UTC-12:00 at epicente

Location
20.561°S 175.730°W depth=103.2km (64.2mi)

Nearby Cities
84km (52mi) NW of Nuku'alofa, Tonga
668km (415mi) ESE of Suva, Fiji
690km (429mi) SE of Lambasa, Fiji
782km (486mi) ESE of Nadi, Fiji
855km (531mi) SSW of Apia, Samoa

Technical Details