Mauna Loa Trivia
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50 free Mauna Loa trivia questions with answers — geography quiz, new questions added Aug 2026.
Mauna Loa is the largest active volcano on Earth, and this quiz covers everything about the Long Mountain: how tall it really is from the sea floor, why its slopes are so gentle, the fish its caldera is named after, the 34 eruptions since 1843, the lava that nearly reached Hilo in 1984, the 2022 eruption that ended a 38-year silence, and the observatory on its flank where the modern record of carbon dioxide began. Easy questions ask which island it stands on and what kind of volcano it is; harder ones dig into George Patton's bombing plan of 1935, the wartime gag order of 1942, the botanist who first reached the summit in 1794 and the two undersea giants that have since bumped it down the size rankings. It suits geography and science quiz nights, Hawaii travellers and anyone who watched the 2022 eruption on the news. Every answer has been checked against the Wikipedia articles on Mauna Loa, its eruptions, its observatory and its neighbours, and each question shows its source once you have answered.
30 of 50 questions with answers and explanations. Play the quiz
Q 01What does the name Mauna Loa mean in Hawaiian?
Long Mountain
Its neighbour Mauna Kea, the White Mountain, is only about 125 feet taller at the summit.
Q 02Mauna Loa is one of how many volcanoes that form the Island of Hawaii?
Five
Kohala is the oldest and Kīlauea the youngest above water; Kamaʻehuakanaloa is still growing beneath the sea.
Q 03Mauna Loa holds which record among the world's volcanoes?
Largest active volcano by mass and volume
It was long thought the largest volcano of any kind until the submarine Tamu Massif was found to be bigger.
Q 04Which two volcanoes were ranked larger than Mauna Loa by 2020, pushing it to third?
Pūhāhonu and Tamu Massif
Pūhāhonu is a mostly submerged shield in the Northwestern Hawaiian Islands; Tamu Massif lies 1,600 km east of Japan.
Q 05What shape of volcanic edifice is Mauna Loa, built by very fluid lava?
A shield
Its very fluid, silica-poor lava builds a broad dome whose slopes are only about 12 degrees at their steepest.
Q 06Measured from its base on the sea floor to its summit, roughly how tall is Mauna Loa?
About 9,170 metres
That beats Everest's 8,848 metres, and the mountain's mass depresses the crust a further 8 km, so its true height is around 17,000 metres.
Q 07Roughly what fraction of the Island of Hawaii's surface area does Mauna Loa make up?
More than half
It covers 5,271 square kilometres and spans up to 120 km across.
Q 08What is the name of Mauna Loa's summit caldera?
Mokuʻāweoweo
It formed 1,000 to 1,500 years ago when a rift eruption drained a shallow magma chamber and the summit collapsed.
Q 09The summit caldera is named after what kind of creature?
A fish
The ʻāweoweo is a red bigeye whose colouring supposedly resembles the caldera's eruptive fires.
Q 10What supplies Mauna Loa's magma?
The Hawaii hotspot
The Pacific Plate's drift will carry the volcano off the hotspot within 500,000 to a million years, and it will go extinct.
Q 11About how long has Mauna Loa been erupting?
At least 700,000 years
It probably broke the ocean surface around 400,000 years ago; some dated rocks are 470,000 years old.
Q 12Which is the island's youngest volcano above sea level, often mistaken for a satellite of Mauna Loa?
Kīlauea
Chemical analysis shows the two have separate magma chambers, though activity at one often coincides with quiet at the other.
Q 13How many times had Mauna Loa erupted from its first documented eruption in 1843 to 2025?
34
Historic eruptions typically begin with a curtain-of-fire fissure before concentrating at a single vent.
Q 21Why did the government gag the local press during the 1942 eruption?
Fear the glow would guide a Japanese bombing raid
It came four months after Pearl Harbor during a blackout; the Army Air Force then dropped sixteen bombs on the flows, to little effect.
Q 22The 1868 eruption coincided with the island's largest recorded earthquake; how many died?
77
The magnitude-eight quake triggered a landslide and tsunami in the Kaʻū district.
Q 23The 1872 to 1877 eruption was unusual for what reason?
It lasted about 1,200 days without leaving the summit
Q 14When did the first Mauna Loa eruption since 1984 take place?
November to December 2022
It began at 11:30 pm on 27 November in the summit caldera and ended on 13 December.
Q 15How long was the record quiet spell that ended with the 2022 eruption?
38 years
Magma had been building beneath the volcano since 1984, and unrest was noted from 2019.
Q 16Which cross-island highway did the 2022 lava flows threaten but never reach?
Saddle Road
The main flow front stalled about 1.7 miles short of it on 8 December before draining away.
Q 17How close did the 1984 lava flow come to the city of Hilo?
Within about 6 km
The glow lit the city at night, but two natural levees upstream broke and diverted the flow.
Q 18How long did the 1984 eruption last?
22 days
Tremor was so strong that the telescopes on Mauna Kea, 40 km away, could not be stabilised.
Q 19The 1950 eruption reached the ocean, 24 km away, in roughly how long?
About three hours
It emitted 376 million cubic metres of lava in 23 days and permanently destroyed the village of Hoʻokena-mauka.
Q 20Which future general planned the 1935 bombing of Mauna Loa's lava to protect Hilo?
George S. Patton
The observatory declared the bombing a success when the lava stopped a week later; volcanologists have disputed that ever since.
It produced more than twice the lava of the 1950 eruption, but never threatened anyone.
Q 24Where did a strange one-day eruption of 1877 take place?
Underwater in Kealakekua Bay
Onlookers in boats saw turbulent water and floating blocks of hardened lava within a mile of shore.
Q 25Which city is partly built on Mauna Loa lava flows from the 1880 to 1881 eruption?
Hilo
At the time the settlement was a shoreside village further downhill and was unaffected.
Q 26Mauna Loa is one of the 16 sites on which watch-list drawn up by the IAVCEI?
Decade Volcanoes
The list identifies volcanoes worth special study for their destructive history and closeness to populated areas.
Q 27Who founded the Hawaiian Volcano Observatory in 1912?
Thomas A. Jaggar
He persuaded the Army to build a summit route in 1915, and declared Patton's 1935 bombing a success.
Q 28Which unit helped build the trail to the summit of Mauna Loa in 1915?
The Buffalo Soldiers
Many of the routes laid out then are still used by scientists today.
Q 29Who led the first recorded successful ascent to the summit in February 1794?
Archibald Menzies
The botanist on Vancouver's expedition estimated its height at 4,156 metres with a barometer, remarkably close to today's 4,169.
Q 30Which Scottish botanist reached the summit in 1834 via the ʻAinapō Trail?
David Douglas
The man behind the Douglas fir stayed overnight to measure the caldera, though his figures proved wildly wrong.