Thursday, 11 February 2010

Forest Eater

My time at HVO is almost up. I have just three weeks left. Whilst here I have developed two GIS models using ArcGIS Model Builder. The first is a probability model to map the probability that an area will be impacted by lava flows, The second is a lava channel model which predicts where lava will flow if there is an eruption by analysing a digital elevation model (DEM). I will post more about these models once they are completed.

Last week we went out to the Kilauea East Rift Zone flow fields. In the days previous to the trip some incredible lava flows had been viewed in the vicinity. The volcano was however now in deflation phase which meant that lava viewing may not be as good. Kilauea undergoes deflation-inflation events or DI events. These events represent phases of inflation and deflation of the volcanic system as magma fills the system and then leaves the system via lava flows or dropping back down into the deep magma chamber. These DI events are captured by GPS units and tiltmeters dotted around the volcano. Despite being in a deflation phase there was luckily still amazing sights to be seen on the flow field. The photo above shows a pāhoehoe lava stream flowing down the pali (cliff) just below the Royal Gardens subdivision.

The lava stream was feeding the a'a flow seen above. This a'a flow was moving slowly down the pali consuming any trees that were its in path. Its easy to understand how the Hawaiian God, Ai-laau which means forest eater got his name.

At the base of the pali on the costal plain there were abundant surface pāhoehoe flows like the one shown above. On my previous trips these surface flows have been hard to find but on this occasion they seemed to be beyond count with new breakouts appearing all the time.

images courtesy of USGS