The Weekly Volcanic Activity Report: April 30–May 6, 2025
New activity/unrest was reported for 6 volcanoes from April 30 to May 6, 2025. During the same period, ongoing activity was reported for 20 volcanoes.
Explosions and pyroclastic flows at Santa Maria volcano, Guatemala
High-level explosive activity at Santa María’s Santiaguito dome complex on May 6, 2025, produced ash plumes up to 900 m (2 950 feet) above the crater and pyroclastic flows down the southern and southwestern flanks.
Tectonic link found between Ontong Java Plateau and Louisville hotspot chain
A new study from the University of Maryland and the University of Hawaiʻi has revealed surprising connections between two major volcanic features in the Pacific. By tracing the Louisville hotspot as the source of both the Ontong Java Plateau and a series of underwater volcanoes, the researchers have uncovered fresh insights into the Pacific Ocean’s geological history. This discovery challenges old ideas and offers a clearer picture of how the seafloor and the islands above it have formed over millions of years.
First real-time observation of volcanic eruption on a mid-ocean ridge
Scientists aboard the Alvin submersible witnessed an active volcanic eruption at the Tica hydrothermal vent on April 29, 2025, along the East Pacific Rise. The event, which buried a vibrant ecosystem under fresh lava, marks the first confirmed real-time observation of such an event on a mid-ocean ridge.
Unrest at dormant Uturuncu volcano driven by gas and fluid movement, not magma
A new study published in PNAS provides the most detailed view to date of the dormant Uturuncu volcano in southwestern Bolivia, revealing that its long-standing ground deformation and seismic unrest are driven by the movement of hot fluids and gases, not by magma ascent. Researchers conclude there is no immediate eruption risk, but confirm that a deep magmatic system remains active beneath the surface.
Axial Seamount showing signs of approaching eruption as magma builds up off Oregon coast
Axial Seamount, an underwater volcano off the Pacific Northwest coast, could erupt soon for the first time in a decade. Scientists at the University of Washington have detected a sharp increase in small undersea earthquakes and seafloor inflation — signs of magma buildup within the volcano. Despite the activity, experts say there is no threat to coastal communities. The site remains under constant observation through one of the world’s most advanced ocean monitoring systems.
The Weekly Volcanic Activity Report: April 23–29, 2025
New activity/unrest was reported for six volcanoes from April 23 to 29, 2025. During the same period, ongoing activity was reported for 21 volcanoes.
Hot mudflows destroy rubber and rice crops in North Sumatra, sparking fears of another Lapindo disaster, Indonesia
Hot mudflows struck Indonesia’s Roburan Dolok village in North Sumatra on April 25, 2025, damaging crops across the region and contaminating the water supply of four villages.
Mount Etna eruption intensifies with lava fountains and ash emissions, Italy
Strombolian activity at Mount Etna’s Southeast Crater evolved into lava fountaining on April 30, 2025, producing ash emissions and prompting a temporary elevation of the Aviation Color Code to Red. This was the 11th eruptive episode at Etna since March 15.
Bulusan volcano erupts, triggers pyroclastic flow and ashfall in Sorsogon Province, Philippines
A phreatic eruption occurred at Bulusan volcano, Philippines, on April 28, 2025, generating a 4.5 km (1 650 feet) high ash plume and resulting in ashfall over nearby communities. The Philippine Institute of Volcanology and Seismology raised the Alert Level to 1.
