Day 9:  September 13, 2005

Reporting:

Lynn Oschmann, Andrew Pomroy, Leah Ziegler

We parked the vans after driving them to the entrance to the active lava flows. From the road (in the dark) the ocean entry lava was visible as a red glow with steam and two breakouts were visible as red glows along the flow from Pu’u O’o to the ocean.

Arrived at the first breakout where we saw pahoehoe toes propagating down the hillside. The toes would stall, inflate, then crack and squeeze out to continue flowing, quickly forming a thin black crust on top of the bright orange lava. The lava was so fresh in this area that the rubber soles were burning off our boots! Hubert sacrificed his walking stick for science, sticking it into a stalled pahoehoe toe. This caused the toe to inflate and outgas, water first, followed by methane. Some of the gases were also mixed into the lava, lowering its viscosity, so that it flowed out of the crack created by the stick. A section of a nearby small tumulus broke off, resulting in a fresh surface flow. Many of us took this opportunity to brave the molten lava by sticking it with a rock hammer.

After a break to eat and rehydrate, we made our way roughly west over to the 2nd breakout, which showed two skylights, one large and one small, open on the side of a lava tube. Within the skylight, the colors were bright yellow and orange and we were unable to approach close enough to look into it as it was extremely hot. In fact, we could see the heat radiating from the skylights from several hundred meters away.

At this location, there was a sizeable cliff, or “pali,” which showed prime examples of entrail pahoehoe. Ropy pahoehoe typically forms during the younger, faster moving stages of a flow, while entrail pahoehoe will typically form at the tail end of a flow, when it has become more sluggish. While viewing the pali, we were standing on a tumulus from a lava flow that appeared to be younger than the entrail pahoehoe, as it overlay the pali flow. However, another hypothesis suggested that perhaps the pali flow went underneath the base flow, pushing it upwards and causing the tumulus to form.

We stopped briefly at this location to view an example of blue glassy basalt at the base of a tumulus. The glassy basalt appeared to have flowed out from underneath the tumulus. The blue sheen forms on quenched pahoehoe as it goes through rapid radiative cooling.

We arrived back at the cars about 10:20. This hike was particularly difficult (ass-kicking), due to the rough terrain and the early departure, but all agreed that it was well worth the effort to see the active flows.