Coastal Life of the Pacific Coast

About the Pacific Coast The word “beach” often conjures an image of a long, narrow strip of sand along the ocean, but beaches can also be made of pebbles or rocks. The Pacific Coast’s incredible features—from sea stacks to tidepools and from huge gray whales to tiny mole crabs—draw visitors from around the world. A great diversity of lifeforms make their home here, and even more species migrate along the Pacific Coast. Many birds use a north-south migratory route known as the Pacific Flyway, and, offshore, some whale species migrate between arctic and tropical waters. How Our Beaches Formed Over millions of years, the Pacific Coast was created by strong natural geologic forces, including volcanic activity. For a long time, scientists have studied how the earth’s crust is made of multiple large plates called “tectonic plates” that are always moving. Colliding plates can push land up to create mountain ranges, like the Coast and Cascade ranges, or push land down to create deep trenches, like Monterey Canyon. When the pressure of collision builds, plates can slip past each other causing an earthquake. The largest of these plates is the Pacific Plate, followed by the North American Plate. The outer edge of the Pacific Plate, dubbed “the Ring of Fire,” contains 75% of the world’s active volcanoes. A smaller plate called the Juan de Fuca Plate sits between the two major plates to the west of Washington and Oregon. Erosion is another force that has shaped the Pacific Coast. Wind and water wear down rocks and sand in coastal watersheds into finer material over time. This material is transported along waterways until it is deposited at the ocean’s edge, forming a beach.