PREVIEW

A renewed burst of volcanic activity at Kīlauea has delivered one of the most dramatic displays seen during the current eruption sequence, which has lasted almost a year.

Episode 38, which unfolded on 6 December, featured rare “tephra-nadoes” - small, tornado-like vortices whipped up by swirling winds within the ash and cinder plume.

A USGS field crew working along the southern rim of Halemaʻumaʻu crater captured the fleeting phenomenon as it twisted skyward beside a powerful lava fountain. The whirling column formed when turbulent air currents interacted with dense tephra fallout, creating a brief but striking vortex against the backdrop of incandescent lava.

From the Kīlauea Overlook in Hawai‘i Volcanoes National Park, the scale of the transformation is even more apparent. Freshly deposited tephra continued to steam across the crater floor as inclined fountains from the south vent arced high above the rim.
A buoyant ash-laden plume rose above the eruptive centre, while a new puʻu- a small volcanic hill - emerged along the crater’s edge. Downwind, volcanic gases refracted sunlight into a brownish haze stretching across the horizon.

According to the US Geological Survey, Saturday’s activity began at around 08:45 HST, when lava surged from the north vent. Four minutes later, the south vent ignited with fountains that quickly soared more than 300 metres (1,000 feet), leaning southward over a closed section of the national park. By late morning, the north vent fell silent, leaving the south vent to continue projecting lava nearly 280 metres (920 feet) into the air.

The intensity of the episode sent sulfur dioxide emission rates above an estimated 50,000 tonnes per day - high enough to generate a towering plume reaching more than 6,000 metres (20,000 feet) above sea level.

The National Weather Service and the Washington Volcanic Ash Advisory Center issued special notices, while Hawaii County Civil Defense warned of the potential for fine volcanic glass particles falling in communities downwind.

For scientists at the Hawaiian Volcano Observatory, the latest eruption episode provides both spectacular viewing and critical data.