HANA LAVA TUBE
The Hana Lava Tube is a great place to visit with your family. The cave is spectacular and there are many interesting rock formations that you will see inside. The terrain isn't too challenging and the return trip can easily be done in less than 45 minutes with lots of time to stop and take photos. The Hana lava tube is the 18th largest lava tube in the world and the largest in Maui!!
The Hana Lava Tube is open year-round from 10:30 am until 4:00 pm, 365 days per year and it is privately owned and operated. There is an admission fee to get into the cave and you will be given a flashlight to use on your self-guided tour. Handrails are located at many locations inside the cave to assist you on your hike and there are a number of informational signs along the way. There is also a visitor centre and a picnic shelter overlooking the Red Ti Botanical Garden Maze.
Lava Tube Formation
A lava tube is a type of volcanic cave which can be quite long and complicated. A lava tube is formed from a channel of lava flowing downhill away from a volcanic eruption or fissure. Over time the top of the lava flow will cool and crust over in a surface flow but the river of lava will continue to flow underneath as it remains at a high temperature. Once the source of lava flow ends, the channel will drain out leaving a lava tube. Lava tubes develop best in lava that is highly fluid, usually a basaltic type which is known as “pahoehoe”. In pahoehoe lava flows, the molten rock contains a solution of volatile components which decrease the rate at which the lava solidifies. It also has a lower viscosity so there is less friction between the molecules and the lava flows more quickly.
Lava tubes are usually located near the ground surface so they are very susceptible to erosion so most existing lava tubes are fairly recent in geological terms. Due to erosion, it is common for the roof to collapse in weaker areas leaving behind “skylights” and larger collapses or sinkholes can become an entrance to the cave system. In the picture below you can see a volcano vent. The actual scientific name of this opening is an internal lava tube rupture. It was not caused by erosion but instead due to a blowout from within due to the backup of pressure when a large boulder got jammed in a narrow passage.
Unique formations can occur as the remaining lava cools. In the Hana lava tube you will see many interesting formations which are accompanied by signs giving information about how these formations developed. The floor in places here has a ropey surface and the pattern was formed as the last of the lava flow hardened in place. In one area, a pillar was formed when a huge boulder broke off from the sidewall and got stuck in the passage and the lava flowing around it on both sides added layers. Lava dripping from the roof of the tube hardened to form lava stalactites in spots which haven't changed since the tube formed. Some of the lava stalactites though are extended at the tips by the growth of calcite stalactites from dripping water. The picture below shows some of the lava stalactites you will see in this lava tube.
To log this Earthcache, e-mail or message answers to the following questions to the cache owner and post a photo.
Question 1:
- Describe the lava stalactites in the cave in terms of colour, appearance and length but do NOT touch them.
- Are the lava stalactites made of rock that is igneous, sedimentary or metamorphic?
Question 2: In the “Bowling Alley” area of the lava tube, the lava flow spilled into one of the gutters for a distance of about 8 feet. What colour is the spill and what substance does that indicate is present?
Question 3: Do the lines of the ropey pahoehoe run parallel or perpendicular to the direction of the lava flow through the lava tube and why?
Question 4: Give one example of an effect of erosion that you observed and where you observed it.
Question 5: Take a photograph of you, your GPSr, a trackable, or some personal item at any of the rock formations inside the cave or at the cave entrance. In light of the June 2019 revised earthcache guidelines, this is a mandatory component of this earthcache. Logs without a photo may be deleted. Please do not include a picture of the informational signs though.
Logs will be deleted if an e-mail containing the correct answers isn't received within a reasonable period of time. Also, please be respectful of the area when you are visiting. Thanks!! I hope you will enjoy your visit to the Hana Lava Tube and also learn something in the process!
Acknowledgements:
Thanks goes out to the management and staff of the Hana Lava Tube (aka: Ka' Eleku Cavern) for approving this earth cache!
References:
“Hana Lava Tube.” www.mauicave.com/.. N.p., n.d. Web. 17 Mar. 2020.
William B. White. “Volcanic Caves.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 13 Mar. 2020, www.britannica.com/science/cave.
Bruce Rogers, United States Geologic Survey.
"Lava Tube." Wikipedia. Wikimedia Foundation, n.d. Web. 14 Mar. 2020.
