Lōʻihi Seamount, an active submarine volcano, represents a dynamic geological and biological frontier hidden beneath the Pacific Ocean. This underwater mountain is a site of ongoing growth, marked by frequent seismic activity. It hosts unique ecosystems supported by unusual energy sources, demonstrating life’s adaptability in extreme environments.
Geological Characteristics and Location
This active submarine volcano is situated approximately 35 kilometers (22 miles) off the southeastern coast of the island of Hawaiʻi. Its summit rests about 975 meters (3,200 feet) below the ocean’s surface. Lōʻihi is the youngest volcano in the Hawaiian-Emperor seamount chain, a volcanic line stretching to the northwest.
The seamount’s formation is directly linked to the Hawaiian hotspot, a deep magma plume beneath the Earth’s crust that has been responsible for creating the entire Hawaiian chain over the last 70 to 85 million years. Lōʻihi began forming around 400,000 years ago as the Pacific Plate moved slowly over this hotspot. The volcano experiences frequent earthquake swarms, with notable events in 1971-1972, 1975, and a particularly intense swarm in 1996 involving over 4,000 earthquakes.
Life at the Hydrothermal Vents
The seamount is home to active hydrothermal vents, openings in the seafloor that release superheated, mineral-rich fluids from the Earth’s crust. These vents create stark temperature gradients, ranging from warm diffuse flows (5-100 degrees Celsius or 41-212 degrees Fahrenheit) to plumes of extremely hot water (250-400 degrees Celsius or 482-752 degrees Fahrenheit). Life around these deep-sea vents thrives through a process called chemosynthesis.
Chemosynthesis involves microorganisms, primarily bacteria and archaea, deriving energy from chemical reactions using compounds like hydrogen sulfide, hydrogen gas, and ferrous iron present in the vent fluids. These microbes form the base of a unique food web, acting as primary producers in a lightless environment. Complex animal communities have adapted to these conditions. For instance, mats of bacteria and archaea coat the vent surfaces, and unique species such as ʻōpaeʻula shrimp swarm these areas, feeding on the microbial mats.
Becoming the Next Hawaiian Island
Lōʻihi is continuously growing due to ongoing volcanic eruptions. It is following the same developmental pattern observed in other Hawaiian volcanoes. Currently, the summit of Lōʻihi stands over 3,000 meters (10,000 feet) above the ocean floor.
Scientists estimate that this submarine volcano will eventually breach the ocean’s surface and become the next Hawaiian island. Projections suggest this emergence could occur in approximately 10,000 to 100,000 years.
Cultural Significance and Naming
The seamount’s name has evolved to reflect its deep connection to Hawaiian culture and traditions. Originally known as Lōʻihi, meaning “long” in Hawaiian, a name given in 1955 based on its physical shape, it was officially renamed Kamaʻehuakanaloa in July 2021 by the Hawaiʻi Board on Geographic Names. This change was prompted by Hawaiian scholars who found historical references to the volcano in ancient chants.
Kamaʻehuakanaloa translates to “the glowing child of Kanaloa,” a powerful name rooted in Hawaiian creation stories. Kanaloa is the deity associated with the ocean, while Pele is the goddess of volcanoes. The new name highlights the volcano’s birth from the sea and its connection to these significant cultural figures.