The question of whether Mauna Loa is taller than Mount Everest is common, highlighting the complexities of measuring Earth’s mountains. Mount Everest, situated in the Himalayas, is universally recognized as the highest point on the planet. However, the Hawaiian volcano, Mauna Loa, is a strong contender for the title of the world’s largest mountain. The answer depends entirely on the method used to define and measure a mountain’s height: elevation above sea level versus its total vertical dimension.
Measuring Height Above Sea Level
The standard, universally accepted metric for comparing mountain heights is elevation above mean sea level. This measurement determines the world’s highest point, a title securely held by Mount Everest. Its official elevation was most recently established through a joint effort by Nepal and China in 2020. This measurement places the summit at 8,848.86 meters (approximately 29,032 feet) above sea level. This immense altitude is why Mount Everest, which straddles the border between Nepal and China, is famously referred to as the “roof of the world.”
Measuring Height from Base to Summit
A completely different picture emerges when measuring the total vertical distance from a mountain’s true geological base to its summit. This alternative measurement reveals the scale of Mauna Loa, the largest active volcano on Earth, located on the island of Hawaiʻi. The vast majority of its structure is submerged beneath the Pacific Ocean, making its visible height above the water misleading.
The volcano’s summit rests at about 4,170 meters (13,680 feet) above sea level, only a fraction of its true height. Mauna Loa’s flanks descend an additional 5,000 meters (16,400 feet) to the ocean floor. Measuring from the seafloor base to the peak, the volcano stands approximately 9,170 meters (30,085 feet) tall, surpassing Everest’s elevation by hundreds of feet.
Furthermore, the mountain’s immense weight has caused the oceanic crust beneath it to be depressed by an additional 8,000 meters (26,000 feet). Accounting for this crustal depression, the total vertical relief of Mauna Loa from the bottom of its foundation to the summit is 17,170 meters (56,000 feet). This confirms Mauna Loa as the world’s most massive single mountain, composed of an estimated 65,000 to 80,000 cubic kilometers of rock.
Distinct Geological Origins
The difference in height, mass, and shape between Mauna Loa and Mount Everest is a direct result of their distinct geological origins. Mount Everest was formed by the collision of the Indian and Eurasian tectonic plates. This process, which began approximately 50 million years ago, is an example of a convergent boundary where continental crust is crumpled, folded, and thrust upward.
The resulting formation is a towering, jagged peak with relatively steep slopes, characteristic of the Himalayas. This ongoing tectonic activity continues to raise the mountain by a few millimeters each year. This mechanism created extreme elevation above the surrounding land but did not require the massive volume of rock extending deep into the crust that Mauna Loa possesses.
Mauna Loa, by contrast, is a shield volcano that formed over a stationary hot spot in the Earth’s mantle. As the Pacific plate slowly moved over this plume of magma, the volcano was built up layer by layer by frequent, highly fluid lava flows. This low-viscosity lava spread out widely, creating a mountain with broad, gentle slopes and immense volume. The slow, continuous accumulation accounts for its colossal mass, much of which is hidden below the waves, explaining its dominance in total size rather than sheer elevation above sea level.