Ethiopia’s Hayli Gubbi erupts suddenly; here are Earth’s largest volcanic eruptions and their impacts

Ethiopia’s Hayli Gubbi volcano erupted suddenly on 23 November 2025, surprising observers across the Afar Region. A thick ash plume rose nearly fifteen kilometres, drifting across the Red Sea and reaching several nations. Flights were delayed, air corridors were diverted and haze spread far from the remote crater. The eruption marked the first confirmed activity from the volcano in almost twelve thousand years.

Scientists noted the plume’s reach across the Arabian Peninsula. Ash and sulphur dioxide moved further east toward India and Pakistan. Aviation authorities across several countries reported heavy disruptions. The event raised questions about hazards from long-silent volcanoes. It also renewed public interest in past explosive eruptions across Earth’s long history.

History’s biggest volcanic eruptions
Here are ten major eruptions that shaped climate and human history. Each entry carries details about size, impact and global effects.

• Mount Tambora, Indonesia (1815)
  This eruption reached a VEI of 7 and released about one hundred cubic kilometres of debris. Global skies dimmed in 1816, causing the “Year Without a Summer”. Widespread crop failure followed, with more than seventy-one thousand deaths reported.


• Lake Toba, Indonesia (c. 74,000 years ago)
  The eruption rated VEI 8 and formed today’s Lake Toba. It is seen as the largest explosive event in the past twenty-five million years. Its ash and gases triggered long climatic cooling across the planet.


• La Garita Caldera, USA (c. 2.1 million years ago)
  This VEI 8 eruption in Colorado is viewed as one of Earth’s largest known volcanic events. The Fish Canyon Tuff formed from massive ash deposits. The eruption reshaped western landscapes on a continental scale.


• Yellowstone Caldera, USA (last major event around 640,000 years ago)
  Yellowstone produced several VEI 8 eruptions over time. Ash from past events spread across much of western North America. The caldera remains closely monitored for signs of activity.


• Mount Mazama, USA (c. 5700 BC)
  This eruption collapsed the mountain and created Crater Lake. Vast ash layers settled across the Pacific Northwest. The event influenced regional ecosystems for centuries afterwards.


• Taupō Volcano, New Zealand (Oruanui eruption c. 26,500 years ago)
  The Oruanui eruption reached VEI 8 and is the largest known in the last seventy thousand years. Ash spread widely across the region. The eruption altered landscapes across New Zealand’s North Island.


• Samalas, Indonesia (1257)
  The VEI 7 eruption from the Samalas system created a major sulphate spike in ice cores. It may have influenced climate patterns linked to the early Little Ice Age. Ash likely reached distant continents.


• Mount Thera (Santorini), Greece (c. 1610 BC)
  This VEI 7 eruption devastated nearby islands and shaped the Aegean world. Many believe it contributed to the fall of the Minoan civilisation. The blast formed the present Santorini caldera.


• Changbaishan / Baitoushan, China–North Korea border (c. AD 1000)
  Often called the Millennium Eruption, this VEI 7 event sent ash across Asia. The explosion altered regional climate and lake systems. It remains one of the largest eruptions of the past two thousand years.


• Krakatoa, Indonesia (1883)
  This VEI 6 eruption produced one of history’s loudest recorded sounds. The blast triggered massive tsunamis, killing more than thirty-six thousand people. Ash coloured skies globally for months afterwards.