What is Tephra?

Episode 43 of the ongoing Halemaʻumaʻu eruption has produced significant tephra fall across Hawaiʻi Volcanoes National Park and surrounding communities.

The eruption led authorities to raise alert levels and issue road closures and ash fall warnings as winds carried ash, Pele’s hair, and volcanic debris toward Puna, Hilo, and the Hamakua Coast.

What is Tephra?

According to the United States Geological Survey (USGS), Tephra is a general term for all fragments of volcanic material ejected into the air during an eruption. The word originates from the Ancient Greek term tephra, meaning “ashes.”

Tephra can vary widely in size and form, including:

• Volcanic ash – fine particles that can travel long distances
• Cinders – larger fragments that can blanket nearby areas
• Volcanic bombs – large molten rocks that solidify in the air before landing

Impacts of Tephra

Different types of tephra can have significant environmental and societal impacts:

• Ash clouds may reach the upper atmosphere, temporarily cooling temperatures and disrupting air travel.
• Cinders can cover ecosystems and communities, potentially causing health problems and infrastructure damage.
• Volcanic bombs can directly damage buildings, roads, and other structures due to their size and impact force.

Source: USGS