Two more earthquakes shook California on Thursday, marking the latest in a burst of seismic and volcanic activity along the Ring of Fire.
An earthquake of magnitude 4.0 took place just after 2 to 31 miles southeast of Anaheim, according to the United States Geological Survey. And an earthquake of 5.8 shook about 100 miles off the coast of Humboldt County at 8:39 a.m. Tsunamis are not expected, according to a Twitter publication by the National Tsunami Warning Center.
A magnitude 6.2 earthquake in Japan follows on Wednesday and a 7.9 magnitude earthquake in Alaska on Tuesday triggered a rapidly canceled tsunami warning for the west coast. Major earthquakes have also been reported in Indonesia and Chile this week.
In addition, volcanic eruptions in the Philippines, Indonesia, Bali and Japan continue to spew ash and lava, forcing the evacuation of tens of thousands of people. Tuesday's eruption of Mount Kusatsu-Shirane in Japan killed a soldier and wounded more than a dozen people, including several at a nearby ski resort.
The United Nations Office for Disaster Risk Reduction tweeted a warning that the Ring of Fire was "active".
What is the Ring of Fire?
The Ring of Fire refers to an extensive area of horseshoe-shaped geological disaster in the Pacific, according to ABC News. The ring extends 25,000 miles from New Zealand through Indonesia, the Philippines and Japan to Alaska, Canada and the west coast to South America. It contains 452 volcanoes and several tectonic plates in the earth's crust.
Adjusted like a jigsaw puzzle, the tectonic plates change and collide constantly, producing earthquakes.
Scientists say that the recent series of earthquakes and volcanic eruptions are merely commercial for the Ring of Fire.
"It so happens that these events happen at the same time in different parts of the region," Chris Elders, a geology expert at Curtin University in Australia, told the BBC. "There is not necessarily a relationship between them."
Janine Krippner, a volcanologist from New Zealand based in the United States, reminded people that "they do not call it a 'ring of fire' because they are there doing nothing."  It is not known as the "ring of fire" because it is there doing nothing. It is an area in constant movement, very active (and huge) full of faults and active volcanoes. It is normal to have so much activity. https://t.co/GjY5wFBWZF
– Dr Janine Krippner (@janinekrippner) January 24, 2018