Mauna Kea, an inactive volcano in Hawaii, is the world’s tallest mountain as measured from its base, deep in the Pacific Ocean, to its summit. Mauna Kea’s summit is at 13,796 feet (4,205 meters) above sea level, but it extends about 19,700 feet (6000 meters) below the water’s surface.

Mauna Kea only stands 13,796 feet above seal level, but the mountain extends about 19,700 feet below the Pacific Ocean. Over half of it is submerged. That puts the total height of Mauna Kea at about 33,500 feet — nearly a mile taller than Everest.

Mauna Kea Volcano rises 13,796 feet (4,205 meters) above sea level but extends about 19,700 feet (6,000 meters) below sea level to meet the deep ocean floor. Mauna Loa Volcano stands not quite as high as Mauna Kea but is much larger in volume.

13,678′

Summary. Mauna Loa on the Island Hawaiʻi is the world’s largest volcano. People residing on its flanks face many hazards that come with living on or near an active volcano, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and local tsunami (giant seawaves).

Hawaii’s Mauna Loa volcano killed 77 people in the course of an 1846 eruption, 46 as a result of a volcanogenic tsunami and 31 from volcanic mudflows. Since 1998, four people have died there as a result of the venting of deadly carbon dioxide gas.

Which volcanic eruptions were the deadliest?

Mount Tambora

Mount St. Helens

Yellowstone is not overdue for an eruption. The rhyolite magma chamber beneath Yellowstone is only 5-15% molten (the rest is solidified but still hot), so it is unclear if there is even enough magma beneath the caldera to feed an eruption. If Yellowstone does erupt again, it need not be a large eruption.

Harry R. Truman Truman

Taylor died on the evening of July 9, after four days of suffering from symptoms that included severe cramping, diarrhea, nausea and dehydration. His personal physicians concluded that he had succumbed to cholera morbus, a bacterial infection of the small intestine.

According to the United States Geological Survey (USGS): “We know that Mount St Helens is the volcano in the Cascades most likely to erupt again in our lifetimes. He said: “Yes, it is extremely likely that Mt St Helens will erupt again. The average eruption recurrence interval is every 100-300 years.”

Fifty-seven people

The water in Spirit Lake was completely displaced by the avalanche and heated to body temperature. Blast felled trees were swept into Spirit Lake as water displaced by the landslide receded. Widespread oxygen depletion occurred as bacterial populations responded to increased nutrient levels.

An increase in the frequency and intensity of felt earthquakes. Noticeable steaming or fumarolic activity and new or enlarged areas of hot ground. Subtle swelling of the ground surface. Small changes in heat flow.

The resulting steam-driven eruption, also called a hydrothermal or phreatic eruption, can happen suddenly and with little to no warning. The expansion of water into steam is supersonic in speed and the liquid can expand to 1,700 times its original volume. This produces catastrophic impacts.

Helens: 40 Years of Recovery.

Pyroclastic flows can kill people up to a distance of six to nine miles (10-15km) from the volcano. Lahars are among the most far-reaching phenomena, with deadly effects over a mean distance of more than 12.5 miles (20km).

Unlike the ash produced by burning wood and other organic materials, volcanic ash can be dangerous. Its particles are very hard and usually have jagged edges. As a result, it can cause eye, nose, and lung irritation, as well as breathing problems.

Biological hazards are extremely dangerous. These include exposure to dangerous substances and diseases associated with working amongst animals, people, or infectious plant materials. Employees who work in hospitals, laboratories or various other outdoor occupations are at risk from biological hazards.

Lava is molten rock that flows out of a volcano or volcanic vent. Depending on its composition and temperature, lava can be very fluid or very sticky (viscous). Fluid flows are hotter and move the fastest; they can form streams or rivers, or spread out across the landscape in lobes.

In short bursts humans can run at 32 km/hr (20 miles/hr). So people could easily walk, jog or run away from almost all lava flows…. unless they are in situation such as a steep sided very narrow valley leading to a volcanic event that is churning out basaltic lava at a huge rate.

Lahars and excess sediment cause serious economic and environmental damage to river valleys and flood plains. Over a period of weeks to years after a volcanic eruption, the erosion and transportation of loose volcanic deposits can lead to severe flooding in areas far downstream from a volcano.

Another type of nonexplosive volcanism is flood basalts. Lava flows from this type of eruption are extruded from fissures and cover vast areas. These nonexplosive eruptions are the least dangerous type of volcanic eruption since people rarely get killed by them (Francis, 1993).

Since it tends to flow more as a thick liquid it can pour uphill as well as downhill and can create a huge variety of interesting shapes. If pahoehoe lava flows over a fairly flat ground it will coat the ground much like a parking lot – with a thick, smooth, flat coating of lava.

What are the hazards from volcanoes?

• Lava. Lava (molten rock) can erupt as fire fountains or lava flows (when it is runny) or as steep-sided domes (when it is viscous).
• Pyroclastic flows.
• Phreatic explosions.
• Lahars.
• Jökulhlaups.
• Landslides.
• Volcanic earthquakes.
• Tsunamis.

Carbon dioxide gas can collect in low-lying volcanic areas, posing a lethal risk to humans and animals. However, even if magma never reaches the surface, gases can often escape continuously into the atmosphere from the soil, volcanic vents, fumaroles, and hydrothermal systems.