Currents Are King
The islands are teeming with life in part because of where they formed. The Galápagos Islands sit at the intersection of several major ocean currents—some warm, some cold.
The climate depends on these currents. And the currents are influenced by the winds that push them.
Let’s start with the Humboldt current. It sweeps north from Antarctica up the western edge of South America and carries cold, nutrient‑rich water.
The Humboldt is a deep‑water current. With powerful trade winds, it creates an effect called upwelling. Winds blow ocean water at the surface away. Then deep‑sea water rises up to replace it. Upwelling helps create a rich marine ecosystem. As ocean organisms die, they sink to the bottom. The deep sea is then filled with nutrients. Upwelling brings that water to the surface. The nutrients provide food for tiny organisms called phytoplankton, the first part of the ocean food chain.
Peru Oceanic current
South Equatorial current
Cold water holding nutrients rises up to replace water that is pushed away.
Surface winds push water away from the land.
Strong winds mix with deep currents to create upwelling. The ocean becomes plentiful with food.
When Currents Collide
From May through December, the Humboldt collides with the warm‑water Panama current. The Panama current flows south from Central America. When these two currents meet, they create a cool mist. Clouds form over the islands. The islands seem to disappear.
Meanwhile, the Cromwell current moves in from the west. It travels thousands of kilometers from Hawaii. The current slams into the islands, upwells, and swirls around them. This deep‑water, cold current also carries nutrients to feed the marine food chain.
Galápagos penguins and fur seals live along the western shores of Isabela and Fernandina. Here, the upwelling is strongest. The water is cooler here, too.
At the same time, the South Equatorial current flows east to west through the Galápagos. This warm‑water current is a major surface current in the Pacific.
Around December, the warm Panama current becomes dominant. It brings high humidity and heavy tropical rains that can usher in El Niño.
The waters and currents moving around Galápagos Islands support life.
Wait. El Niño? Another ocean current? Not really. The El Niño current only forms every few years. This current affects weather patterns. It can bring more rain and possible flooding. El Niño can last for months at a time.
El Niño can benefit plant life on the islands by bringing rain. This leads to population booms for animals that eat them.
During a harsh El Niño, the Humboldt current is cut off and upwelling can’t happen. That means there isn’t enough food for sea animals. They die in great numbers. At the same time, big rainfalls make dry lowlands green. Land animals and small birds thrive.
The Galápagos are a place where nature fights to stay in balance. It was born of fire. It is fueled by wind and water. It is always full of life.