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.

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.

A powerful storm system drenched Southern Nevada on May 6, triggering flash flood warnings, airport delays, and a swift-water rescue in Henderson after a man was swept into a wash and disappeared. Rainfall totals shattered multiple records across the Las Vegas Valley, with Harry Reid International Airport logging the highest May rainfall in over five decades.

Mt Hutt experienced an unusually intense snowfall from May 2 to 4, 2025, with accumulations reaching 1.2 m (48 inches). This marks a record for early May snowfall in the area, according to Mt Hutt Ski Area. The storm system also brought damaging winds and flooding to parts of the country, with power outages affecting more than 1 100 homes, particularly in the Wellington region.

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.

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.

Antarctica has shown a rare shift in behavior, gaining ice mass between 2021 and 2023 after years of steady decline. Using satellite gravimetry, researchers tracked this anomaly and linked it to unusual precipitation rather than long-term change. The findings offer insight into the continent’s sensitivity but little certainty about what comes next.

Wildfires burned over 2 500 ha (6 200 acres) across North Dakota’s Turtle Mountain and Fort Berthold reservations in early May 2025, threatening homes. Coordinated efforts by state, tribal, and federal agencies saved most structures, with only one abandoned trailer lost.

Severe thunderstorms swept across Texas on Monday and Tuesday, May 5–6, 2025, triggering flash floods and widespread damage across the state. In Brenham, a 10-year-old girl who went missing after being swept away by floodwaters on Monday was found deceased the following day.

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.

Severe thunderstorm warnings and tornado watches have been issued for parts of Texas, including Dallas-Fort Worth, Austin, and Houston on Tuesday, May 6, 2025, as an omega block weather pattern drives widespread storms across the region.