Mauna Loa

mauna loa from hilo bay

Mauna Loa summit in snow 2016

Volcano in Moonlight

Mauna Loa taken from the 9300 ft level on the ascent of Mauna Kea

Mauna Loa from the air

Aa channel flow from Mauna Loa

Mauna Loa is one of the five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. Being the largest subaerial volcano in both mass and volume, Mauna Loa has historically been considered the largest volcano on Earth. It is an active volcano and has erupted 33 times since its first well-documented eruption in 1843. Its most recent eruption occurred in 2022.

Mauna Loa's massive size and shield volcano shape are a result of thousands of years of lava flow accumulation from its magma chamber. The volcano's name, Mauna Loa, means "Long Mountain" in Hawaiian, a fitting name for a volcano that stretches over 120 km (75 miles) from the southern tip of the island to the summit and then down the north-eastern flank.

Geology and Eruption History

Mauna Loa is a shield volcano, a type of volcano usually built almost entirely of fluid lava flows. It rises 4,169 meters (13,678 feet) above sea level, making it the second highest peak in Hawaii, just slightly lower than its neighbor Mauna Kea, which is considered the tallest mountain on Earth when measured from its base on the ocean floor.

The volcano is part of the Hawaii hotspot, which has been responsible for the creation of the Hawaiian Islands over tens of millions of years. Mauna Loa's magma comes from the Earth's mantle, which melts due to the hotspot's heat, creating magma that rises through the Pacific Plate to reach the surface and erupt.

Eruptions at Mauna Loa are typically non-explosive and are characterized by the outpouring of lava flows that can cover large areas. However, these eruptions can pose significant hazards to nearby communities due to lava flows and volcanic gas emissions. The 1950 eruption is one of the most significant in its recorded history, with lava flows reaching the ocean in less than three hours.

Environmental Impact and Monitoring

The United States Geological Survey (USGS) closely monitors Mauna Loa for signs of activity. The Hawaiian Volcano Observatory (HVO), part of the USGS, uses a variety of tools, including seismographs, gas sensors, and satellite imagery, to track the volcano's behavior.

Mauna Loa's eruptions have significant impacts on the environment. Lava flows can destroy vegetation and alter landscapes, while volcanic gases like sulfur dioxide can create vog (volcanic smog), posing health risks to humans and animals and affecting air quality. Despite these hazards, the volcanic soil is very fertile, supporting diverse ecosystems and agriculture in areas not currently threatened by lava flows.

Cultural Significance

Mauna Loa holds great cultural importance for the Native Hawaiian people. It is considered a sacred place, featuring prominently in local mythology and traditions. The summit area is believed to be the home of the volcano goddess Pele, and many cultural sites are located on its slopes.

Tourism and Recreation

Despite the potential dangers, Mauna Loa and its surrounding areas are popular destinations for tourists and outdoor enthusiasts. The Hawaii Volcanoes National Park encompasses the summit and much of the volcano's flanks, offering hiking trails, camping sites, and the opportunity to observe volcanic activity in a relatively safe environment.

Conservation

Efforts to conserve the unique ecosystems on Mauna Loa involve controlling invasive species, protecting native flora and fauna, and managing human activities that can lead to environmental degradation. The park and surrounding areas are managed to balance conservation efforts with the needs of research, tourism, and cultural practices.