Over the last 100 years, the Global Volcanism Program at the Smithsonian Institution has recorded hundreds of eruptions worldwide—most of which were modest and received little global notice. Yet twelve of these events were large enough to cause significant loss of life, widespread property damage, and lasting environmental change.
According to the U.S. Geological Survey (USGS), Mount Novarupta’s 1912 eruption released an estimated 21 km³ of volcanic material—more than thirty times the volume of the 1980 Mount St. Helens event—making it the largest volcanic explosion in the United States during the 20th century.
Between 1914 and 1917, Lassen Peak’s series of eruptions produced lava and debris flows that covered over 16 km². While the flows reached residential areas, structural damage remained limited, a fact noted by the USGS.
On May 18 1980, the lateral blast from Mount St. Helens destroyed the upper 396 m of the volcano, killing 57 people. The ensuing debris avalanche blocked the Columbia River, halted shipping, and damaged highways and rail lines. The USGS estimates that the blast obliterated 596 km² of land across Washington and neighboring states, with ash drifting as far east as North Dakota.
In 1983, Kilauea’s eruption spread lava across 78 km², destroying 180 buildings. A subsequent 1990 eruption leveled the entire community of Kalapana. The USGS reports that these events added 121 km² of new land to the island of Hawaii.
Mauna Loa erupted for three weeks beginning March 25 1984. Lava flows threatened Hilo but ultimately caused no major damage, according to the USGS.
Although mudflows from Nevado del Ruiz had devastated Armero in 1595 and 1845, the 1985 eruption was the deadliest. Lahars killed 23,000 people, the largest volcanic death toll in modern history. The volcano’s history is documented by the Smithsonian’s Global Volcanism Program.
When Augustine Volcano’s summit collapsed into the ocean in 1986, it generated a 9‑meter tsunami that reached 80 km away. Ash plumes disrupted air traffic and drifted over Anchorage, but no fatalities were reported and property damage was minimal.
Redoubt’s 1989‑1990 eruptions caused a temporary shutdown of the Drift River Oil Terminal and produced ash plumes that affected regional air traffic; other damage remained minor.
Mount Pinatubo’s Level 6 eruption in 1991 was mitigated by a robust early‑warning system, resulting in only 350 deaths—mostly due to collapsed structures—despite its massive ash plume.
The first eruption of the Soufrière Hills Volcano in 1995 unleashed pyroclastic flows that forced evacuations and destroyed Montserrat’s capital, Plymouth. The event is extensively documented by the USGS.
NASA’s Earth Observatory reports that Chaitén’s 2008 eruption sent ash and steam plumes soaring 16.76 km (55,000 ft) into the atmosphere. The ash blanket reached the town of Chaitén, ten kilometers away, yet no casualties were recorded.
Eyjafjallajökull erupted for almost four months in 2010. The volcano’s heat melted glacier ice, generating floods from meltwater and ash. A plume that rose nearly 11 km disrupted air travel across the North Atlantic, prompting several countries to close their airspace for days.
These eruptions illustrate the varied ways volcanoes can reshape landscapes, disrupt economies, and challenge emergency response systems worldwide. For more detailed eruption histories, visit the Smithsonian Global Volcanism Program and the USGS Volcano Hazards Program.
