Big Pacific – Violent Pacific

Watch the second episode of Big Pacific, “Violent Pacific,” on your local PBS station at 8pm Eastern, Wednesday, June 28th. The companion book is now available from Princeton University Press.

Drowned Forest

The stumps of these spruce trees are remnants of the forest drowned by the 1700 earthquake

Although its name suggests calm and tranquility, the Pacific Ocean is riven by powerful natural forces: violent tropical storms, volcanic eruptions, and earthquakes are common occurrences across this mighty ocean. The ocean sits within the Ring of Fire, a zone of intense tectonic activity where multiple plates meet, grinding and driving against each other with sometimes cataclysmic results. Running in a horseshoe shape from New Zealand along the western Pacific to the Aleutians and back down the western coast of the Americas, the Ring of Fire is home to 90% of the world’s earthquakes. All but three of the 25 largest volcanic eruptions in the last 12000 years have occurred in the Ring of Fire, the eruptions of Tambora and Krakatoa among them. The power and destructiveness of these eruptions and quakes is monumental—in 1700 an earthquake in Cascadia caused the coastline to drop by as much as ten feet in a matter of seconds, instantly submerging wide swathes of forest beneath the water. The shockwave took only ten hours to cross the thousands of miles of ocean to reach the coast of Japan in the form of a massive tsunami.

humpback whales

The long pectoral fins of the humpback whale can be used as weapons by battling males.

The life of animals in the Pacific can be no less violent. The struggle for survival manifests both as competition within species, and between species. It is easy to think of humpback whales as placid animals, drifting through the ocean in search of the minuscule plankton on which they feed. Their mournful song is a cliché of New Age relaxation tapes. But competition between male humpbacks over females often turns to battle: during their “heat run” contending males will swipe each other with their long pectoral fins, ram each other, and even breach the surface of the ocean to land on each other. Despite the huge bulk of these animals, mature males weighing in at up to 36 tonnes, they can move surprisingly quickly, reaching speeds of 18 miles an hour. The impact of their collisions is comparable to that of fully-loaded eighteen wheeler trucks. The victorious male earns the right to mate with the female.

Shedao Island pit viper

A Shedao Island pit viper claims another victim

But the archetypal struggle in the animal kingdom is that between predator and prey. Evolutionary adaption has made the predators at the top of the food chain near-perfect killers. The Shedao Island pit viper is found only on one tiny island in the Yellow Sea off the coast of China, where it has so effectively dominated the ecosystem that it is estimated that there is one viper for every square meter of land on the island. The sole source of food for these snakes is migratory birds: twice a year, in spring and fall, birds use Shedao Island as a staging post on the journey to and from their breeding grounds in Siberia. These two six-week periods are the only point in the year at which the viper eats. Motionless and near invisible on the branches of a tree, the viper waits for a bird to land. Its strike is near instantaneous and its victim quickly succumbs to the snake’s powerful venom. The viper will slowly swallow its meal whole, then seek another; it must consume several birds to survive the long fast between migrations.

Discover more of the violent side of the Pacific in Wednesday’s episode of Big Pacific.