This stroll comes under the we don't know what it is yet category. You won't find this stroll on any map in the Hawai'i Volcanoes National Park - but it is worthwhile to anyone interested in volcanoes and how the earth works.
A few feet from your car, you will encounter a steaming world of utter destruction. Where once a proud forest of 'Ōhi'a stood is now nothing more than a decayed under carpet and twisted bizarre stumps with bright red fungus and white mineral deposits.
Important Notes: Avoid walking on any plants. The area is still home to fragile native and non-native plants. This area is also of historical and cultural importance to the native hawaiians. If you see hawaiian practitioners at the site please visit at a later time.
To find the Puhimau Thermal Hotspot Stroll take Highway 11 to Volcano and enter the Hawai'i Volcanoes National Park. Once you pass the park gatehouse make the first left onto Crater Rim Drive. Continue on Crater Rim Drive 3 miles until the intersection with Chain of Craters Road. Turn left onto Chain of Craters Road and proceed approximately 1.3 miles. You can see the Hotspot as the trees suddenly give way to only dead grass on the right side of the road, you might see steam. Because this is not an official sight in the Park, there is no official parking. We recommend parking either at Puhimau Crater (at the .9 mile marker after you turned onto Chain of Craters Road) or just past the hotspot area near the cattle guard sign, in the small gravel pullout.
Once you are parked, walk to the hotspot and scramble across the 10 or 15 feet of small ground brush and up onto the hotspot. You will notice one or two narrow paths that have been created by people going to the hotspot, follow them. (There is actually a 4-wheel road, which can take you further back into the hotspot, but it is extremely overgrown and it is just much easier to enter from the paved road.)
Click here to view a map
This hike is a rambling stroll. The actual hotspot area we estimate to be about 50 acres and growing - but the part most interesting currently is near the road to perhaps 500 yards from the road. You will basically just wander around the field, from item to item.
Things To Be Careful Of
The following are general cautions and warnings for this trail:
There are some fissures in the ground as well as holes that used to be trees. Do take care walking around to be sure of what you are walking on.
Do not enter any steaming areas. The steam can be quite hot and burns are easy to come by.
The ground is very spongy to walk on - and in some spots you might be unsure what you are walking on. As far as we can tell this is nothing more than the layer that is left from the rotting forest that once stood there.
What You Will See
Quite frankly, we don't know! This spot is changing every day. Certainly it is not getting any healthier - the destruction is spreading and you can see evidence of this by the fact that it has now started killing trees on the other side of the road.
The Puhimau Thermal Hotspot was first noticed in May of 1938 by Dr. Thomas Jaggar after earthquakes in the area. The original affected region was estimated to be about 15 acres of dying growth. Since 1938 the area has grown slowly and is now 50 to 100 acres in size.
So what is going on under the ground at this Hotspot Stroll? This area of land is near the fault zones, and most likely overtop or near to an underground channel of magma. The USGS estimates that the magma might be as shallow as 500 to 600 feet below the surface. The ground is hot enough to have completely destroyed a forest in a very short period of time (a matter of a few years). The ground itself is a weird spongy soft material. In some places you can sink into the ground a couple of inches - and it feels quite pleasurable, if not a bit disconcerting to walk around. The effect is especially noticeable around areas where stands of trees once stood. You might notice that the ground in places is warm to the touch - this is evidence of the closeness of the magma under the surface.
At the time of this writing (May 2004) there were fissures to the right of the Hotspot that are steaming a great deal. Quite a few plants are enjoying the steam - those that are far enough from the destructive heat.
As you walk away from the fissures, and more towards the center of the hotspot, you will see what remains of trees. Most trees are, quite simply, gone. What is left is merely the soil and holes in the ground. Some of the holes do contain stumps and the stumps are quite amazing to look at.
Most of the stumps are bizarre twisted shapes and almost all are hollow - as if eaten from the inside by the steam. Almost certainly this is what occurred. The steam and heat eventually rotted the inside of the tree causing it to act like a pipe killing the rest of the tree off. You can see plenty of evidence of fallen dead trees next to hollow stumps.
The insides and outsides of some of these stumps are a combination of rotting wood, a bright red fungus (at least we believe it is a fungus) and a white calcite-like mineral deposit. The white mineral deposit is quite interesting and coats the tree stumps like frosting on a cake. Other mineral deposits can be found in some stumps that are bluish and greenish.
So what might this be? Well, this area might be the site of a new pit crater such as Devil's Throat, which is just down the road from the hotspot and is most likely on the same fault.
In a pit crater, the magma traveling through tubes and the fissure below the area causes the area to finally collapse into a huge pit hundreds of feet deep.
However, pit craters rarely have lava in them - rather they have lava below them. The hotspot may be too hot to be a pit crater. Instead, perhaps the hotspot is a new vent or cone.
Whatever the answer is, the area continues to get bigger and disintegrate more each day. Something climatic is sure to happen here sometime soon.