Hawaiian Volcano Observatory
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Watching Lava Enter the Ocean Can Be Dangerous

Active lava delta, Kilauea Volcano, Hawai`i
March 25, 1999
Active Lava Delta and Laze Plume
Kilauea Volcano

Stay Alert -- Stay Alive

When a series of explosions early on March 8 began blasting lava into the air from the edge of the active lava delta on Kilauea Volcano, seven people were seen running for their lives. Even as lava bombs landed all around them in darkness, they luckily reached safe ground without injury. Then, in the next couple of hours, the entire area where they had been standing and running collapsed--about 10 hectares of new land fell into the sea. The explosions and collapse event (see eruption update) are reminders that the ocean entry area is extremely dangerous.

In order to view the entry area safely, people are advised not to venture onto the active lava delta and to be aware of events that can occur with little or no warning. The seven visitors mentioned above were on the delta, far beyond the warning signs posted by the National Park Service.

New land created by lava entering the sea may look like a stable platform. Called a lava delta or bench, this new land may extend a few tens to hundreds of meters into the ocean. But what can't be seen is the loose pile of rubble underneath that supports the delta. This pile of material often slides away, especially when the growing delta advances over a steep submarine slope. Areas the size of several football fields can collapse into the ocean with little or no warning.

Active lava delta, Kilauea Volcano, Hawai`i
March 25, 1999
People viewing active lava delta from the edge of the March 8 collapse scarp, which could also fall into sea during a future collapse event. Warning signs of the National Park Service are at least 50 m upslope (right).

During a collapse event, anyone standing on an active lava delta or even just behind the former sea cliff or scarp from a previous collapse event can be swept into the sea, splashed with scalding water, or hit by flying rock debris. Visitors to the active lava delta should not venture onto the new land. Entry points can be viewed safely only from behind the former sea cliff and shoreline, which are often buried under new lava flows and very difficult to identify. For your personal safety, pay attention to the signs posted landward of the entry area by the National Park Service.

To learn why these areas are potentially hazardous, see:

Collapse of new land into the sea
Explosions at lava entry points
Waves send scalding water onto new land

The most current Volcano Watch article.

The Probability of Lava Inundation at the Proposed and Existing Kulani Prison Sites, 1998, USGS Open File 98-794.

If you felt an earthquake and would like to report it, go to the Earthquake Felt Report Form. We encourage you to submit such reports, which help us determine the intensity of the earthquake.

Previous Feature Stories.

Photo of Reginald Okamura
Collection of Memories Submitted by Friends

In Memory of "Reggie" Okamura

Reginald ("Reggie") T. Okamura, beloved Chief of Operations of the Hawaiian Volcano Observatory from 1958 - 1992, died peacefully in his sleep at Hilo Medical Center on January 16, 1999.

We are keenly aware of the many people "out there" who have been at HVO--alumni, students, volunteers, visiting scientist, administrators, and friends--who have stories they would like to share about Reggie. We are, therefore, creating a section on our web site, where such recollections can be sent for all to remember him by. Please send your stories and scanned or duplicate photos to by March 31st.

At the top of each page are clickable titles that will take you to pages not found on our vertical or bottom navigational bars. Please check out "Hawaiian Volcano Observatory" above to find out more about HVO and the exciting work we do!

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For kids ages K-12, or for those young at heart, see Volcano World's Kids Door. You can do many enjoyable activities to learn about volcanoes.

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Updated: 4 April 2000 (SRB)