Our bus tour Monday afternoon took us to the Volcanoe National Park. You are looking at a view of Halema`uma`u from the Jaggar Museum overlook. The plume color switched from brown to white some weeks ago.... and has been mainly white since. The white plume still carries ash, but the rock fragments are hydrothermally altered lava that is white in color.
One of the primary components in volcanic gas is water. At the vent, the plume is transparent, because it is very hot and the water is in vapor form. A short distance above the vent, however, the plume cools and the water vapor condenses into tiny droplets. This makes the plume an opaque white, just like regular clouds in the sky. These clouds basically cover Kona (other side of the island) each day and make it seem like a rain storm is coming. The cloud like matter though, is simply from the volcanoe.
On this day, Peg and I walked through a lava tube from a volcanoe that erupted years ago. The tube was 15 feet high in some places. The night before heading into Hilo, the ship pulled up close to where the lava from another volcanoe is flowing into the sea (and making the island bigger). The dark night picture with the fire inside is a scene from our cruise ship balcony at 1AM in the morning. We were actually much closer (and scared some people) but I was a little late with the camera as this picture was taken after the ship started sailing away from the shore.
Our tour bus driver should be working as a geologist, and not driving a bus. It was a VERY informative tour and I know more about volcanoes now than I can even describe. This experience was much like watching glaciers break off in Alaska and fall into the ocean.
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