The Always Active Ring of Fire

The Ring of Fire circles the Pacific Basin in a 40,000km (25,000 mi) series of deep ocean trenches and active fault lines from New Zealand to the southern tip of South America. The trenches and fault lines occur where two tectonic plates meet. In most cases, it is an oceanic plate such as the Pacific Plate pressing into and pushing under a continental plate such as the North American or Eurasian Plate that causes trouble. This constant pressure creates the stress that from time to time causes a fault line rupture resulting in a catastrophic earthquake often followed by a tsunami.

In November, 2016, two strong earthquakes hit on the Ring of Fire. The first was a magnitude 7.8 that struck New Zealand’s South Island near Christchurch on November 14. The quake triggered a tsunami that caused little damage, but the quake itself caused massive infrastructure damage and killed two people.

One week later, on November 21, Japan had a magnitude 7.4 earthquake that occurred in the same area as the disastrous 2011 magnitude 9.0 earthquake and tsunami. Although the November 21 quake was felt as far away as Tokyo, it caused no serious damage or loss of life.

The four strongest earthquakes on record all happened on the Ring of Fire. The strongest recorded since modern record-keeping began in 1900 was the magnitude 9.5 Valdivia quake that struck along the coast of Chile on May 20, 1960. It devastated Chilean infrastructure, killed 6,000 people, triggered a 25m (82 ft) tsunami that washed away villages along the Chilean coast, started landslides in the Andes Mountains, and sent a 10.7m (35 ft) tsunami rippling out across the Pacific, hitting Hawaii, Alaska, Japan, and the Philippines 10,000km (6200 mi) away.

The second strongest ever recorded was the Great Alaska Earthquake of March 27, 1964. A magnitude 9.2, the quake resulted from a massive fault line rupture in the Aleutian Trench off the southern coast of Alaska. The Aleutian Trench marks the convergence of the Pacific and North American Plates. The tsunami wave generated by the earthquake reached a height of 67m (219 ft) in one Alaskan inlet. Several coastal villages were wiped out and had to rebuild on higher ground. 131 people died.

The Indian Ocean earthquake of December 26, 2004 was the third strongest on record, but by far the most destructive. A massive 1,000km (600 mi) rupture along the boundary between the oceanic Burma Plate and the continental India Plate triggered a magnitude 9.1 earthquake and a killer tsunami, taking 230,000 lives in 14 countries bordering the Indian Ocean. Indonesia and Thailand were especially hard hit. 15 to 30m (50 to 100 ft) tsunami waves washed far inland, catching many by surprise. The Indian Ocean had no tsunami warning system in place at the time.

On March 11, 2011, the east coast of Japan was hit by the fourth strongest quake on record, followed by a highly destructive tsunami. Waves up to 40m (133 ft) washed 10km (6 mi) inland, causing the Fukushima nuclear power plant to go into meltdown. Authorities reported 19,000 dead or missing, and 230,000 displaced due to massive infrastructure damage and radiation danger. The fault line rupture took place in the Japan Trench where the Pacific Plate meets the continental plate underlying the island of Honshu. The quake was so strong it elevated Japan’s main island of Honshu 3m (10 ft) and moved the island 2.4m (8 ft) east.

More than 10,000 earthquakes occur on the Ring of Fire each year. Most are minor quakes of magnitude 5.0 or less. We don’t know exactly where or when the next big one will strike, but it will not be a surprise if it is somewhere on the Ring of Fire.