Mauna Loa, located on the Big Island of Hawaii, holds the title of the largest volcano on Earth. It is a shield volcano, characterized by its broad, gently sloping sides, and covers an area of about 5,271 square miles (13,678 square kilometers). While Mauna Loa’s towering peak reaches 13,681 feet (4,170 meters) above sea level, its true size extends much deeper—around 33,500 feet (10,210 meters) from the seafloor, making it taller than Mount Everest if measured from its base.
Mauna Loa is part of the Hawaiian-Emperor seamount chain, a series of volcanoes formed as the Pacific tectonic plate moves over a hotspot, or an area of intense heat within the Earth’s mantle. The volcano has been erupting for at least 700,000 years, and its most recent eruption occurred in November 2022. While Mauna Loa is one of the most active volcanoes in the world, its eruptions tend to be non-explosive, producing slow-moving lava flows that can last for days or even weeks.
The sheer size of Mauna Loa is awe-inspiring. Its massive volume is estimated at 18,000 cubic miles (75,000 cubic kilometers), and it makes up about half of the Big Island’s landmass. This volcanic giant has had a significant influence on the local environment and human history. Native Hawaiians have long regarded Mauna Loa as a sacred place, and its eruptions have shaped the island’s geography and ecosystems over millennia.
The lava flows from Mauna Loa have created vast, barren landscapes, but over time, these areas have become home to a diverse range of plant and animal species, including some that are found nowhere else on Earth. Despite the potential danger of eruptions, Mauna Loa’s slopes are home to towns and communities, as well as important astronomical observatories that benefit from the clear skies and high elevation.
Due to its size and activity, Mauna Loa is closely monitored by scientists. The Hawaii Volcano Observatory tracks seismic activity, gas emissions, and ground deformation to provide early warning of future eruptions. This monitoring is essential to protecting the people and infrastructure on the Big Island.
Mauna Loa stands as a testament to the incredible power of Earth’s natural forces. Its size and frequent activity make it an important feature in the study of volcanology and a vital part of Hawaii’s cultural and natural heritage.