Hawaiian Geology

Welcome to the most isolated group of islands in the world! The Hawaiian archipelago is made up of 137 islands and numerous atolls, coral reefs, boulders, and underwater seamounts that extend over 1,500 miles long and are 1,860 miles away from any continents. What makes our islands unique is the way in which they are formed. Just like the locals, Hawaiian volcanoes are also very “laid back.” Hawaiian lava flows are generally slow moving, non-violent eruptions where people often enjoy close-up views of the earth’s natural creation.

We know that there are 14 major, and many minor, tectonic plates that float above the mantle creating our earth’s crust. These plates are constantly moving; pulling apart from one another, colliding, submerging, or sliding beside one another. We know that they are moving because of earthquakes. Hawaii sits in the middle of the Pacific Oceanic plate and this plate is moving North West towards Alaska at about 3 inches per year.

What makes Hawaii unique is the way in which the islands were formed. Hawaii volcanoes are shield volcanoes which are the opposite of composite volcanoes such as Mount Fiji in Japan and Mont St. Helens in Washington. Shield volcanoes are characterized by slow moving lava and non-violent eruptions. The lava flows are typically a thick and slow moving basaltic flow creating some the tallest mountains on earth. Big Island’s Mauna Loa is the largest mountain on earth, rising over 13,000 feet above sea level. When measured from the base of the Pacific Ocean, which is where Mauna Loa starts, the mountain’s true height is 56,000 feet high (over 10.6 miles high).

Below the slow moving Pacific Oceanic plate is a stationary “hot spot” or 35 mile long lava tube from the earth’s mantle to the bottom of the Pacific Ocean. Over time a mountain is formed underwater, also known as a seamount, and eventually breaks the ocean’s surface creating an island. Over time this island eventually moves away from the hot spot and another newer island is slowly created. Over the course of time an island chain develops with the older islands being the furthest North and the younger islands being in the south. Today, the Big Island, or Hawaii sits on top of the hotspot, with Kilauea being the most active volcano in the world. It has been erupting over 23 years and is erupting today. Believe it or not we have the newest Hawaiian island, Lo’ihi, being created as we speak. Lo’ihi is 22 miles south east of the Big Island and is about 3,000 feet from the breaking the ocean’s surface. Experts estimate that it will be another 10,000 years before Lo’ihi breaks the surface of the Pacific Ocean creating the newest ocean front property in Hawaii.