Welcome to the magnificent Big Island of Hawaii, home to one of Earth’s most awe-inspiring natural wonders: Mauna Loa volcano. Standing as a testament to our planet’s raw creative power, Mauna Loa is not merely a mountain—it’s a living, breathing giant that continues to shape the very land beneath our feet. Here, you’ll witness geology in action, where the boundaries between earth, fire, and ocean blur into a spectacular dance of creation that has been ongoing for hundreds of thousands of years.
As you explore this remarkable landscape, you’ll be walking on some of the youngest land on Earth, where ancient Hawaiian legends intertwine with scientific discovery. Mauna Loa isn’t just a destination; it’s an experience that connects visitors to the primal forces that have shaped our world since time immemorial. Whether you’re standing on its vast slopes, gazing at its impressive silhouette from afar, or learning about its fiery history, Mauna Loa offers a glimpse into the heart of our planet’s most fundamental processes.
History and the Birth of Mauna Loa Volcano
When and How Was Mauna Loa Volcano Created?
Like a patient artist working over countless millennia, the Pacific Ocean has birthed the Hawaiian Islands through a remarkable geological process. Imagine, if you will, Earth’s crust as a massive conveyor belt, slowly moving over a stationary “hot spot” of molten magma rising from deep within the planet’s mantle. This hot spot is like a blowtorch held beneath a moving sheet of metal, puncturing through to create island after island in a northwesterly chain.
Mauna Loa’s story began approximately 700,000 to 1 million years ago, when underwater eruptions started building this colossal mountain from the ocean floor. Layer by layer, eruption after eruption, this submarine volcano grew until it finally breached the ocean’s surface roughly 400,000 years ago. Since then, it has continued its skyward journey, becoming the largest active volcano on our planet.
I often tell visitors to think of each lava flow as a page in Earth’s diary—each one recording a moment in time when the mountain grew just a little larger. Walking across Mauna Loa’s slopes today, you’re literally traversing through chapters of Earth’s history, with younger flows often overlapping older ones in a complex geological palimpsest that scientists have spent decades deciphering.
What Makes Mauna Loa Volcano So Special?
Mauna Loa isn’t just any volcano—it’s a superlative in nearly every respect. Like a sleeping giant resting after millennia of labor, Mauna Loa stands as the largest active volcano on Earth in terms of volume and area. From its base deep on the ocean floor to its summit, Mauna Loa measures over 30,000 feet (9,170 meters)—making it taller than Mount Everest if both were measured from their bases! When measured by volume, this behemoth contains approximately 18,000 cubic miles (75,000 cubic kilometers) of mountain, making it one of the most massive single mountains in the world.
What truly sets Mauna Loa apart is its classification as a shield volcano—named for its resemblance to a warrior’s shield lying flat on the ground. Unlike the explosive stratovolcanoes like Mount St. Helens, Mauna Loa’s eruptions typically feature highly fluid lava that flows for great distances, creating its characteristic broad, gently sloping profile. This shape is like a drop of water spread wide on a table—extending far but rising gradually. Mauna Loa is a massive shield volcano that rises almost 9 km from the ocean floor to form the world’s largest Holocene volcano. When active, it tends to produce “voluminous, fast-moving lava flows” of the Hawaiian or effusive eruption type rather than more explosive eruptions, though it has produced explosive eruptions between 300 and 1,000 years ago.
The volcano’s name itself speaks to its grandeur: in Hawaiian, “Mauna Loa” means “Long Mountain,” an apt description for a volcano whose slopes extend for miles in all directions. Standing anywhere on the Big Island, this massive presence dominates the landscape, a constant reminder of the powerful forces that have shaped these islands.
What Will Mauna Loa Volcano Look Like in 1 Million Years?
Peering into the geological future is like trying to predict the final shape of a sculpture while the artist is still working—we can make educated guesses based on patterns, but Earth often surprises us. In one million years, Mauna Loa will likely be unrecognizable from its current form.
Like all Hawaiian volcanoes, Mauna Loa is on a predetermined journey through stages of development. Currently in its robust shield-building phase, it will eventually follow its older siblings like Kohala and Mauna Kea into dormancy. As the Pacific Plate continues its northwesterly drift at about 3.5 inches (9 cm) per year, Mauna Loa will slowly move away from the hot spot that feeds it.
In a million years, erosional forces—wind, rain, and waves—will have carved deep valleys into its slopes. The weight of this massive mountain will have caused it to sink somewhat into the ocean floor. Without fresh lava to build it up, Mauna Loa will begin the long process of returning to the sea from which it rose. It may resemble the older Hawaiian islands like Kauai, with dramatic erosional features, lush vegetation, and a significantly reduced height.
I like to tell visitors that volcanoes are like living beings with lifespans—they’re born, they grow, they mature, and eventually, they return to the earth. Mauna Loa is currently in its prime, but in a million years, it will have become a dignified elder in the island chain, bearing the marks of its long and eventful life.
Will Mauna Loa Erupt Again?
When standing on Mauna Loa’s vast slopes, visitors often ask me this question with a mixture of trepidation and excitement. The simple answer is an unequivocal “yes.” Mauna Loa is not a dormant relic of the past but an active volcano that continues to breathe fire. Like a giant who awakens periodically from slumber, Mauna Loa has established a pattern of activity that scientists have documented for generations.
Since detailed records began in 1843, Mauna Loa has erupted 34 times, with its most recent eruption occurring from November 27 to December 13, 2022, after a 38-year period of quiet. The 38-year span between the 1984 and 2022 eruptions was Mauna Loa’s longest period of quiescence on record. This eruption began just before midnight on November 27, 2022, in Mokuʻāweoweo, the volcano’s summit caldera when lava flows emerged from fissure vents. The lava flows ended up traveling 16 miles, stopping 1.7 miles short of Saddle Road, but fortunately did not cause injuries, fatalities, or major property damage, though it did threaten equipment at Mauna Loa Observatory and the cross-island highway.
Volcanologists at the USGS Hawaiian Volcano Observatory continually monitor Mauna Loa for signs of unrest—tracking everything from minute ground deformations to changes in gas emissions and seismic activity. These scientists are like physicians monitoring a patient’s vital signs, alert to any changes that might signal an impending eruption. In fact, prior to the 2022 eruption, scientists detected increased earthquake activity beneath Mokuʻāweoweo caldera beginning in mid-September, with the number of quakes rising from 10-20 per day to 40-50 per day, triggered by magma moving into Mauna Loa’s summit reservoirs The 38-year span between the 1984 and 2022 eruptions was Mauna Loa’s longest period of quiescence on record.
While we cannot predict exactly when Mauna Loa will erupt next, its historical patterns suggest it’s not a question of if, but when. Each period of quiet is simply the volcano recharging, gathering magma in its chambers before the next display of nature’s power. For visitors, this represents both a humbling reminder of our planet’s dynamic nature and an exciting opportunity to witness geology in action during your lifetime.
Things to Do on Mauna Loa
The slopes and surroundings of Mauna Loa offer a treasure trove of experiences for the adventurous traveler. Like an open-air geological museum, this volcano presents opportunities to connect with nature in ways few other places on Earth can match.
For the hiking enthusiast, Mauna Loa offers one of the most challenging and rewarding treks in Hawaii. The trail to the summit is not for the faint of heart—a multi-day journey that takes you through surreal landscapes that shift from lush forests to barren lava fields before reaching the enormous summit caldera. Standing at 13,679 feet (4,169 meters) above sea level, with views that stretch across the Big Island and beyond, you’ll feel as though you’re on top of the world.
For those seeking less strenuous experiences, the Mauna Loa Observatory Road provides access to stunning viewpoints without the demanding hike. This drive takes you through multiple climate zones—a journey that’s like traveling from the tropics to the Arctic in just a few hours. Note that parts of this road may be closed during heightened volcanic activity, so always check with Hawaii Volcanoes National Park for current conditions.
Explore Saddle Road (Highway 200, also known as the Daniel K. Inouye Highway), which cuts between Mauna Loa and Mauna Kea. This scenic 52-mile highway showcases diverse landscapes and provides access to both volcanoes. When Mauna Loa is active, designated viewing areas may be established along this route, as happened during the 2022 eruption.
Photographers will find endless inspiration in Mauna Loa’s landscapes. The interplay of light and shadow across the textured lava flows creates dramatic scenes that change by the hour. At sunrise and sunset, the mountain takes on golden and crimson hues that transform it into a canvas of natural artistry.
Stargazing near Mauna Loa offers another unforgettable experience. The clean, clear air at higher elevations provides some of the best night sky viewing on the planet—a celestial spectacle that has drawn astronomers to Mauna Kea, Mauna Loa’s neighboring peak, for decades.
For those interested in Hawaiian culture, numerous guided tours explore the spiritual significance of Mauna Loa to native Hawaiians. In Hawaiian tradition, volcanoes are the domain of Pele, the goddess of fire and volcanoes. These cultural experiences provide deeper understanding of the profound relationship between the Hawaiian people and the dynamic land they call home. Consider visiting during Lā Kūʻokoʻa (Hawaiian Independence Day) on November 28th, which coincidentally was when many witnessed the 2022 eruption in its early stages.
