Volcanic eruptions and earthquakes in Asia and Alaska over two days show that the Pacific Ring of Fire is "active", said the UN Office for Disaster Risk Reduction on Tuesday (Jan 23).
A powerful quake hit the Gulf of Alaska in the early hours of Tuesday; a relatively shallow magnitude-6 quake struck off Indonesia's Java in the afternoon; and the sudden eruption of Mount Kasatsu-Shirane in Japan killed one person and injured at least 11.
In the Philippines, Mount Mayon continues to erupt, sending lava and larger plumes of ash higher into the sky.
Territories on the Pacific Ring of Fire, where tectonic plates meet, see frequent seismic and volcanic activity.
More than half of the world's active volcanoes above sea level encircle the Pacific Ocean, and about 90 per cent of the world's earthquakes occur in this zone, according to the US Geological Survey.
Japan is one of the world's most seismically active nations and on Wednesday, a magnitude 6.2 earthquake struck off the the island of Honshu, not far from Hokkaido island.
Meanwhile, volcanoes in Indonesia that started to spew ash and smoke late last year continue to rumble in 2018.
Mount Agung in eastern Bali remains on alert for a major eruption and there have been multiple eruptions this month, according to Twitter alerts from Sutopo Purwo Nugroho, a spokesman for Indonesia's disaster mitigation agency.
In an update on Tuesday, Sutopo wrote: "There have been four eruptions on Jan 23, 2018. Caution. The airport is normal."
Mount Sinabung, which suddenly became active in 2010 after lying dormant for 400 years, sent volcanic ash on villages and farmers' crops in North Sumatra's Karo regency in December last year.
In May 2016, an eruption killed seven people, while a February 2014 eruption left 16 people dead.
Sinabung has been rumbling continuously since 2013. Not a day goes by without an explosion at Sinabung, Sutopo tweeted last week.
Another eruption that made the news in recent months was that of Mount Kirishima, a mountain range in Japan's Kagoshima prefecture. Relatively small explosions sent ash over cities and towns nearby as authorities lifted the alert level to three.
The plume of ash was captured on video and posted on Twitter by James Reynold.
A number of other craters are on the boil but minor eruptions, sometimes in remote areas, have gone unreported.
Mount Dukono in Indonesia's Moluccas islands, for instance, has been spewing ash since 1933, according to the Smithsonian Institution. Sakurajima volcano in southern Japan last erupted between Jan 10 and 15.
The USGS weekly volcanic activity update on Jan 16 listed four ongoing eruptions in Asia - apart from Mayon and Agung, there's also Suwanosejima in the Ryukyu Islands and Aira in Kyushu.