While most of us love a trip to the beach and a refreshing dip in the ocean, have you ever stopped at the beach to think how old these huge bodies of water are? Long before the dinosaurs, we explore the world’s oldest ocean.
The mighty Pacific Ocean is the largest and deepest of the world’s ocean basins, as well as the oldest, containing rocks dating back about 200 million years, according to NOAA. The Pacific covers an area of 163 million square kilometers (63 million square miles) and is so large that it could contain all the land on Earth.
The oldest ocean is the Pacific Ocean
The world’s oceans are constantly changing as the tectonic plates in the Earth’s crust move; this means that the Pacific Ocean is actually shrinking as the Atlantic Ocean expands towards it. In the Pacific is an area called the “Ring of Fire” because of the high levels of volcanic and earthquake activity in these tectonic plates.
As the world’s oldest ocean, it also has very old seawater. According to the research, the oldest water in the North Pacific was trapped in a “shadow zone” deep below the surface for about a thousand years.
However, this is still quite young compared to the world’s oldest water. A remnant of the North Atlantic, this ancient H2O was found beneath the Chesapeake Bay in an impact crater that formed 35 million years ago. Scientists believe the water is between 100 and 145 million years old and has always been there, but was released by the asteroid impact and then trapped below. The water is so old that it has twice the salinity of modern seawater.
Also older still is a small piece of the world’s oceanic crust that lies undisturbed in the Mediterranean Sea. Believed to be about 340 million years old, it was formed when hot molten rock called magma arose and then cooled. As it cooled on the mid-ocean ridge, the minerals in the magma became magnetized, allowing researchers to locate the area with their magnetic detection equipment.
