Réunion Island Lava Reaches the Sea

Located 700 kilometers (440 miles) east of Madagascar, Reunion Island is the product of a long-lived mantle hotspot at the bottom of the Indian Ocean. The island first emerged above the ocean surface about 2 million years ago. It remains active today, with frequent eruptions from Piton de la Fournaise, a shield volcano located to the east of the island.

Since the 17th century, the volcano has experienced more than 150 documented eruptions. The most recent began in the Enclos Fouqué caldera on February 13, 2026, with the opening of four fissures that fed sustained lava fountains reaching 10 to 50 meters (30 to 160 ft). In February and March, basalt lava poured over the volcano, advancing through forested and grassy areas toward its eastern side.

This thermal satellite image shows lava flowing east toward the ocean on March 28, 2026. The signal reveals the amount of heat emanating from Earth’s surfaces based on detections of thermal radiation in two wavelengths. Warmer areas are mapped in yellow and colder areas in blue. The thermal data was overlaid on a digital elevation model of the island.

“The hottest areas, represented by the brightest tones, correspond to the eruptive vent, active lava channel and flow front,” said Adele Campus, a volcanologist at the University of Turin. From the vent, lava flows downward for several kilometers, often through lava tubes. “Places where lava reappears on the surface through eruptions appear as localized hot spots,” she added. Campus and colleagues analyzed more than two decades of satellite observations from NASA and NOAA in a 2025 study, identifying key trends and patterns in the volcano’s thermal activity and lava outflow rate.

On March 13, lava crossed the island’s National Route 2 (RN2). By March 16, it had begun pouring into the Indian Ocean, producing acidic plumes of volcanic steam and gases, known as laze, according to the Piton de la Fournaise Volcanological Observatory (OVPF). Scientists on the ground measured lava temperatures of 1,100 to 1,130 degrees Celsius (2,010 to 2,070 degrees Fahrenheit) as the lava approached the ocean. Thermal readings also showed water temperatures exceeding 36°C (97°F) up to 600 meters from the entry point, according to the OVPF. By March 24, material entering the ocean had created a new lava delta that extended the coastline by 190 meters.

“This eruption appears to have been longer and to have produced a larger volume of lava than usual,” said Diego Coppola, professor of volcanology at the University of Turin, co-author of the analysis with Campus. Such characteristics are often associated with the beginning or end of an eruptive cycle. The most recent cycle began in 2014, peaked in 2015 and ended in July 2023. “The current activity,” he said, “likely marks the beginning of a new cycle of frequent eruptive activity at Piton de la Fournaise.”

NASA Earth Observatory image by Michala Garrison, using Landsat data from the US Geological Survey and elevation data from the Shuttle Radar Topography Mission (SRTM). Story by Adam Voiland.

• Airbus Space, via X (March 25, 2026) The volcanic heart of Reunion Island ignites again. Accessed April 1, 2026.
• BBC (2026, March 16) Watch: Réunion resident gets closer to lava from an erupting volcano. Accessed April 1, 2026.
• Global Volcanism Program (2026) Piton de la Fournaise. Accessed April 1, 2026.
• Imaz Press (March 13, 2026) [Photos-Vidéos] Volcano: three flows crossing national road 2, the lava approximately 600 meters from the ocean. Accessed April 1, 2026.
• MSN (March 25, 2026) Lava from the Réunion volcano reaches the ocean for the first time in 19 years. Accessed April 1, 2026.
• NASA Earth Observatory (December 30, 2023) Snow Peak, Reunion Island. Accessed April 1, 2026.
• Piton de la Fournaise volcanological observatory, via Bluesky (2026) Posts. Accessed April 1, 2026.
• Piton de la Fournaise volcanological observatory (2026) Press releases and bulletins. Accessed April 1, 2026.