Saturday, October 2, 2010

~ Surface flow stalled ~ Ocean entry continues on unstable delta ~

ABOVE: (click for larger size)
Aerial image of the ocean entry lava and coastal flats posted on the USGS/HVO Images web page that I have added notes too. (Check their page for some nice aerials looking inside the Pu`u O`o crater that show the crusted but hot lava that has been spilling inside recently. They have also posted some other recent photos and movie clips with informative captions.)
This view from above clearly shows the new lava-created delta of land produced by the continuous outflow from the lava tubes since July 25th this year. As I have posted many times in the past, these new land delta/benches are highly unstable and very prone to partial or even a total collapse without warning. Bench collapses cause violent steam, ash, tephra and scalding waves on a small or large scale The cracking of the hot bench alone can create massive littoral explosions of raw lava and/or powerful ejections of rock fragments for long distances.

Many of my photographs appear to have been taken from the bench while in fact most are recorded through long lenses from the stable older sea-cliff land (see the aerial where the lighter lava bench meets the darker sea-wall land). Though I do take closer images of the lava pouring into the see during the first days it finds the sea before the new delta is formed or is just beginning to form, it is one thing for experienced persons to approach the active lava deltas and another to purposely lead inexperienced island visitors directly out on a hot delta.

Below: Last person of a tour group as they exit the edge of the lava delta.

On every trip out to record the ocean entry these past weeks I have observed tour groups, both early morning and at night, hiking along the coast from the Kaimu/Kalapana vicinity as local guides lead their group of tourists right straight out onto the lava bench, following the contours of the outer delta edge, as they attempt to get as close to the actively pouring lava as they can. Often then proceeding to hike across the entire hot & fuming delta only a short distance inland from the actual ocean entry, as mentioned below. I cringe every time I see this. Not all walk-in tours allow this unsafe practice; always staying a safe distance from the hot bench.

The photo below taken yesterday morning at 5:22 AM from inland looking out across the bench towards the glowing lava steam. Minutes before taking it I watched a tour group of about eight people with flashlights walk all the way across the bench, which by the way had molten sections flowing only yesterday. In the photo you can see some of the lava glowing on the bench as well as a small littoral tephra explosion.

The tour guides that don’t follow safe approaches should watch these two USGS clips: Both movie clips show the violent activity that took place on two separate lava benches that are remarkably similar in structure to our current one --
this delta collapse clip
this explosive eruption of another bench

Small sections of the outer delta/bench have been breaking off over the weeks. A friend of mine recently witnessed a small tour group as they walk away from the most active outer edge of the delta and a moment later the very spot this group had been standing dropped in an instant into the sea; exploding as it did; another close-call of many.

More favorable winds are arriving to the Lower Puna coast but I do not know if the Hawaii County lava viewing area in Kalapana Gardens will open today or not. Try phoning Civil Defense lava hotline after 2:00PM for an update: 961-8093

No comments:

Post a Comment