Earthquakes
The earthquake occurred at 20:25 GMT on Sunday at a depth of 29,7 kilometers (about 18 miles) with the epicenter located in 117 kilometers to the east of the Shikotan island.
There appeared to be no tsunami threat following the earthquake and there were no immediate reports of any damages or casualties. The Geological Survey appointed the green level of the earthquake consequences, indicating low probability of casualties and economic damage.
The so-called Kuril-Kamchatka Arc, which extends some 2,100 km from Hokkaido, Japan along the Kuril Islands and the Pacific coast of Russia's Kamchatka Peninsula, is one of the most seismically active regions in the world.
The sinkhole is estimated to have a depth of 20-30 meters at least, and an overall surface area of around 200 square meters, and is believed to have been caused by a series of earthquakes that struck the region a week ago.
On October 14, Ioannina was hit by a strong tremor measuring 5.4 on the Richter scale and followed by hundreds of aftershocks, some of them quite powerful.

Methane gas bubbling up out of cold seeps on the Atlantic Ocean floor offshore Virginia.
"It's like bottles of champagne all along the seafloor," said Jesse Ausubel, an organiser for the 2016 National Ocean Exploration Forum, where the gaseous discovery, along with other intriguing finds from recent deep ocean surveys, is being presented this week.
For years, scientists have been aware that methane, an odourless, colourless gas produced naturally during microbial digestion (and more famously, by farting cows) bubbles up from the seafloor where the conditions are right. Recent scientific surveys have discovered hundreds of methane seeps along the Atlantic continental margin, and it's believed there could be thousands more across the world.
Understanding these seeps — where and when they occur, and what controls their activity — is a hot topic in Earth science research today, given that methane is a potent greenhouse gas. In fact, many scientists worry that by warming the oceans, climate change is speeding up the very processes that produce methane, in addition to melting icy methane hydrates that accumulate on the seafloor. In theory, this could lead to an enormous release of heat-trapping gases to the atmosphere.
The Hayward Fault has long been considered a threat because it runs under densely populated neighborhoods east of San Francisco. The new work found that beneath San Pablo Bay, it joins with a second, less active underground fracture to the north.
Scientists had already considered the possibility of both faults rupturing at once, whether they are connected or not. So the discovery doesn't change the estimated earthquake hazard much, although it confirms suspicions that the stage is set for what could be a massive quake.
If the Hayward and Rodgers Creek faults broke simultaneously along their combined 118 miles, they could produce a magnitude 7.4 quake, said scientists from the U.S. Geological Survey.
The same source says that the epicenter of the quake was at a latitude of 5.29 degrees south and a longitude of 108 degrees east, 120 kilometers northeast of Subang, 654 kilometers below the sea.
According to the head of Data, Information and Public Relations, the National Disaster Mitigation Agency (BNPB), no injuries nor casualties reported after earthquake. "As of now, there are no victims," he told Tempo via text message.
According to the data from the BNPB, the quake has no potential to cause a tsunami. However, it was felt in several regions in West Java, such as Cikarang, Indramayu, Cirebon, Cianjur, etc.
The earthquake struck at 2:09 p.m. The quake struck 6 miles south-southeast from Ridgemark and 10 miles outside of Hollister, and at a depth of 4.7 miles.
Locals in the Salinas and Hollister area reported weak shaking to the USGS site and there were no immediate reports of damage.
Tuesday's earthquake is the latest in a series of small tremors in the area. The USGS also reported four other quakes in October that centered in Ridgemark. The earthquakes have ranged from the smallest quake measuring at a magnitude-1.7 on Oct. 10, to an earthquake with a magnitude of 2.2 that struck the area on Monday.
The US Geological Survey detected the epicentre near New Britain, Papua New Guinea's largest offshore island, at 4.15pm local time (7.15am BST).
It came days after another tremor measuring 6.4 hit the same region. There was no immediate information on casualties or damage.
The Pacific Tsunami Warning Centre did not release a warning following the earthquake.
"Based on all available data, there is no tsunami threat from this earthquake," a notice said.
Papua New Guinea lies on the Pacific "Ring of Fire" - a volcanically active region subject to requent earthquakes, tsunamis and volcanic eruptions.
In July 1998, two undersea quakes measuring 7.0 on the Richter scale created three tsunamis that killed at least 2,100 people near the town of Aitape.
Earthquakes have historically caused widespread damage across central and southern Greece, Cyprus, Sicily and other neighboring regions.












