Day 4:  September 9, 2004

Reporting:

Alan Podawiltz, Ashley Medin (group 6)

Sulfur Banks; Ground Temperature of Steaming Bluff

Support Files:  A plot of the location of the overall hiking track is given in figure 4-1 and table 4-1, respectively.

The event of today was a stop at the Sulfur Banks. Here there are a multitude of sulfur vents, also known as fumaroles. The vents butt up against the decaying outermost wall of the Kilawea Caldera. The wall was created by a ring fault with about 30 meters of subsidence. This makes the vents be deep enough to tap into the magmatic gases. These gases, mainly hydrogen sulfide and carbon dioxide, cause acid alteration of the surrounding rocks. Furthermore, the breakdown of the rocks into clay happens more quickly under the acidic conditions. The rocks directly next to the vents are covered with bright green sulfur deposits. Vegetation in the area is very limited because only certain plants can grow in such acidic soils.

The Steaming Bluff is a meadow along the Kilawea Caldera edge. The many steam vents there are a result of shallow groundwater interacting with hot rock, not magma. Thus no magmatic gases come out of them and the pH of the ground is relatively neutral. However, large plants still do not grow on much of the Steaming Bluff area since the ground is too warm for tree roots.

For Exercise 3, we did traverses over the meadow of the Steaming Bluff area and took ground temperatures. Each of the eight groups took around 50 points, recording the temperature and the GPS location of every point. The GPS locations of the steam vents were also noted. All of the groups' data will be combined into a contour plot of the ground temperature so that we can investigate the relationship between the steam vents and the ground temperature. Note: the local air temperature was 32.2 degrees Celsius.