At Ha'akulamanu (Sulphur Banks) Trail, you will be treated to a spectacular volcanic experience that will stimulate all of your senses! SEE - the vibrantly colored mineral deposits. FEEL - the heat and moisture of the billowing steam. SMELL(TASTE) - the pungent sulfur of volcanic gasses. And HEAR - the jovial tune of forest birds singing! Parking is conveniently located at the visitor center and access is available 24/7. You will find an easy, smoothly paved trail leading to a boardwalk that bridges over the fumaroles. I highly recommend hiking this trail at sunrise. The steam will really be pumping (especially if it's a chilly winter morning) and you will have this splendor all to yourself! This trail is wheelchair accessible when entering across the street from the Steam Vents parking lot.
GEOLOGY OF VOLCANIC STEAM VENTS
This amazing phenomenon occurs when rain water seeps deeply into the ground and comes into contact with rocks heated by magma. The rocks are so hot that the water is vaporized and it returns to the surface as steam. Here at Ha'akulamanu, volcanic gasses are also emitted with the steam, mixing with it and producing fumes. In 1922, scientists drilled two holes to measure the underground heat in the area. Temperature measurements remained constant at 205° F (96° C) down to 50 feet (15 m!) Fumes emitted here include sulfur dioxide (SO2), which smells like a struck match, and hydrogen sulfide (H2S), which smells like rotten eggs. These two gases react chemically to produce pure sulfur, a yellow mineral known to Hawaiians as kūkaepele, ("the waste of Pele!") Here, highly sulfurous vapors cause sulfur crystals to form where they exit the ground. These crystals can grow to 2 centimeters (0.8 inches) long.
FUMAROLES
The steam vents at Haʻakulamanu are by definition FUMAROLES: any vents in the surface of the Earth or another rocky planet from which hot volcanic gases and vapors are emitted, WITHOUT any accompanying liquids or solids. Interestingly, most fumaroles die down within a few days or weeks of the end of an eruption, but a rare few (such as those around Kilauea) are persistent, lasting for decades or longer. An area containing fumaroles is known as a fumarole field.
The acidic fumes from fumaroles can break down the rock around the vents, producing brightly colored "alteration haloes." Here, mildly low pH reduces the rock to grayish white opal and kaolinite with the original texture of the rock still discernible. You can also see where fumes with significantly lower pH reduce the rock to clay minerals and iron-oxides that produce vibrant reddish hues.
★★★★★★★★★★★★★★★★★★★★★★★★★★
In order to gain credit for this Earth Cache you must message me with the answers to the following questions. If I do not receive your answers, your log will be deleted.
PLEASE NOTE: All questions are meant to be answered while remaining ON THE BOARDWALK. Deviation from the walkway is NOT PERMITTED due to the potential for bodily injury and destruction of the delicate landscape.
1. Suppose you visit this area and notice that there is little to no steam being emitted. What could you deduce about the recent weather pattern here?
2. From the boardwalk, observe the fumarole field and the area immediately surrounding it. Can you see many trees? Please explain the reason for this observation.
3. From the boardwalk, observe the halo on the ground around the fumarole near Waypoint #1. What is the predominant color here? What would you expect the pH of the fumes to be?
4. From the boardwalk, observe the rocks near Waypoint #2. Based on what you see between the rocks, what two gasses do you suspect are being emitted here?
REFERENCES
Haʻakulamanu (Sulphur Banks) (U.S. National Park Service)
https://www.nps.gov/places/haakulamanu.htm
Kūkamāhuākea and Haʻakulamanu (Steam Vents and Sulfur Banks)
https://www.nps.gov/havo/learn/nature/steam-vents.htm
Day Hike - Ha‘akulamanu (Sulphur Banks)
https://www.nps.gov/havo/planyourvisit/hike_day_sulphur.htm
Fumarole - Wikipedia
https://en.m.wikipedia.org/wiki/Fumarole