Cave Reference

Kazumura Cave Facts [1,2]
  • Worlds longest known continuous lava tube
      Total surveyed length = (42.5 mi / 68 km)
    • Main passage length = (25 mi / 40 km)
    • Upper passages length = (17 mi / 27.2 km)
    • Lower passage length = (.5 mi / .8 km)
  • Approximate end to end distance = (20 mi / 32 km)

  • Deepest known cave in the United States
    • End to end depth = (3614 feet / 1101.5 km)
    • Highest elevation = (3700 ft / 1128 m)
    • Lowest elevation = (86 ft / 26.5 m)
  • Floor depth below the surface
    • Floor depth range = (4-100 ft / 1.2-30 m)
    • Main passage depth = (45-50 ft / 13.7-15.2 m)
    • Upper passage depth = (4-35 ft / 1.2-10.7 m)
    • Lower passage depth = (100 ft / 15 m)
  • Highest ceiling = (59 ft / 18 m)

  • Widest passage = (69 ft / 21 m)

  • Tallest lava fall = (45 ft / 13.7 m)

  • Number of lava falls and cascades over (10 ft / 3 m) = 31

  • Cave temperature varies with elevation
      Temperature range = (59°-72°F / 15°-22.2°C)
    • Temperature at 3700 ft = (59°F / 15°C)
    • Temperature at 2600 ft = (65°F / 18.3°C)
    • Temperature at 90 ft = (72°F / 22.2°C)

  • There are five mazes in the cave:
    • Bifurcation Maze,
    • Candle Factory Maze,
    • Root Cellar Maze,
    • Sexton Maze = 1.5 miles (2.4km),
    • Wonderland Maze = over 1 mile (over 1.6km).
  • Glossary of Misc. Terms [3]
    `a`a (pronounced ah-ah)
    A type of lava having a course, crumbly, irregular surface that is covered in sharp spines.
    A process by which lava gradually accumulates on a surface by sticking to, and/or freezing on that surface.
    active lava tube
    In use. Has lava flowing through it.
    A type of lava rock having a low silicon content. Less silicon allows the lava to flow away from the vent and form tubes.
    Any rock that falls from a cave wall or ceiling is called breakdown. In lava tubes, cold air entering the hot tube cracks or shatters the hot rock causing a collapse. The process is similar to dropping an ice cube into a hot liquid.
    Repeated splitting and merging of lava channels or flow lobes, and later tubes. Similar braids can be found in river deltas.
    (loosely applied)- Any naturally formed rock cavity or overhang, large enough to for a person to get into. (strictly applied)- A naturally formed rock cavity large enough for a person and of sufficiently length to experience total darkness.
    The process by which vibrating molecules align themselves in an orderly and repeating fashion.
    down cutting
    Process of physically eroding the floor of a flowing channel or lava tube.
    flow lobe
    The segment of an advancing pahoehoe flow, that forms between inflation events.
    A mineral deposit that is left behind when water flows down a wall and/or across the floor. In lava tubes, flowstone is a secondary deposit. Ice freezing on a surface can also be considered flowstone.
    Magma which has reached the surface is called lava. (Liquid rock.)
    lava cave
    A cave existing in lava rock. Includes: Tubes, tumuli, lava rises, open vertical volcanic conduits, eruptive fissures attached to tubes, hornitos, and extensive tree molds.
    lava flow
    The advancement of erupted lava. (Lava is a liquid, therefore it flows away from the vent.)
    lava rock
    Frozen lava.
    lava tube
    A conduit which forms around flowing lava; and insulates the flow from the cooling effects of the air.
    lava tube cave
    A lava tube that has drained and cooled.
    Molten rock rising through the earth’s crust is called magma.
    “1. A naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. Those who include the requirement of crystalline form in the definition would consider an amorphous compound such as opal to be a mineraloid. 2. Any naturally formed inorganic material, i.e. a member of the mineral kingdom as opposed to the plant or animal kingdoms.” Quoted from: ("Dictionary of Geological Terms Third Edition" by R L Bates, Anchor Press/Doubleday, Garden City New York, 1984.)
    pahoehoe (pronounced pah-hoy-hoy)
    A type of lava having a smooth, glassy surface that can be lumpy or ropey in appearance.
    secondary deposit
    A deposit forming after lava has solidified. A deposit formed by the movement of water.
    sink hole
    The depression left behind when the roof of a lava tube collapses after the lava has drained from the tube.
    A secondary mineral deposit formed in caves.
    A hanging cave formation which is formed as mineral carrying water drips from an over hanging surface. Lava formations are not formed in this manner and therefore should not be referred to as stalactites. (Calling lavacicles stalactites, implies they are formed by dripping water which can be the source of considerable confusion.)
    A cave formation which grows upward from a surface as mineral carrying water drips from above. Lava formations are not formed in this manner and therefore should not be referred to as stalagmites. (Calling dribble spires stalagmites, implies they are formed by dripping water which can be the source of considerable confusion.)
    tumulus (plural: tumuli)
    Generally a three sided section of inflated crust, raised above the surrounding flow.
    Erosion of a wall at its base, which creates an overhang.
    The point at which magma reaches the surface.
    A term related to the thickness of a fluid and its ability to flow. Liquid water has a low viscosity. Lava has a high viscosity.

    The above terms were copied from "Understanding Lava Tubes and Lava Caves" by Harry Shick with the consent of the author.

    Cave Formations [3,4]

    Kazumura is one of the world's most geologically diverse caves. The following list is an incomplete sampling of that diversity.

    Lava which solidifies while flowing over an edge in sheets can form an apron, curtain or drapery.

    When a river erodes a deep trench into solid rock, a canyon is formed. Underground the process is the same.
    Photo courtesy of Rob Ratkowski

    cave rafts
    Any deposit which floats on a cave pool can be called a cave raft. Rafts can be of mineral (pictured) or biological origin. Both types can be found in Kazumura.

    Several types of small crystals can be found in Kazumura. Gypsum is the most common.

    dribble spire
    Lava dripping from a straw or flowing over a fall piles up to form a dribble spire.

    floor patterns
    The texture, color, and patterns in the floor of Kazumura dramatically changes from point to point.

    Lava levels in a tube fluctuate. Each fluctuation deposits a layer of "glaze" on every surface that the lava touches and sticks to.

    gas bubble holes
    When gas trapped behind a thin oxide layer expands, a hole is left behind.

    A trench like feature formed by fluctuations in the lava levels.

    injected lava
    Lava forced into an existing cavity is said to be injected.

    inverted ridge
    A structure resembling the bottom of a boat which forms as lava solidifies below a crack in the ceiling.

    Knobs form in the center of an eddy current either through erosion or accretion.

    lava balls
    Any rock that is incorporated into a lava flow is called a lava ball. Lava balls can either float or sink depending upon their density.

    lava blades
    Lava blades are a rare wind generated feature usually found on scum rings, but they do show up on other surfaces.

    Lavacicles are the lava tube equivalent of a limestone stalactite. Three distinct types of lavacicles have been found in Kazumura.

    lava falls and cascades
    A lava fall is a place where lava flowed over a vertical drop. A lava cascade is a place where lava flowed down a slope.
    Photo courtesy of Rob Ratkowski

    lava straw
    A straw like tube which forms as lava drips from an overhanging surface one drop at a time.

    A vertical deposit which confines the flow to a channel.
    Photo courtesy of Rob Ratkowski

    A gray-black oxide layer which forms on the tube's walls and ceiling.

    Braided lava flows, (flows which repeatedly split and merge), leave behind a maze when they drain. Kazumura has five known mazes.
    opalescent deposit
    A thin translucent opal like coating which forms on cave surfaces.
    Photo courtesy of Rob Ratkwoski

    Pele's hair
    Molten lava that's been stretched into hair like strands are called Pele's hair. In Kazumura, Pele's hair is red.

    plunge pool
    The pool that forms below a fall is called a plunge pool.

    Lava flowing down a sloped surface is called a run.
    Photo courtesy of Rob Ratkwoski

    A dimple eroded into a surface by a flowing liquid is called a scallop.

    scum rings & benches
    When the lava level in a tube stabilizes, a horizontal flow line called a Scum ring is left on the wall. If the levels are stable for a long period of time the scum ring grows into a bench.
    Photo courtesy of Rob Ratkwoski

    Lava which has been stretched like taffy results in spindles.

    slumping oxide layer
    An oxide layer is like the skin on a paint. Trap enough liquid behind that layer and it will slump and crinkle.

    splash rings
    A rock falling into lava leaves an impression called a splash ring.

    squeeze ups
    Any lava cave feature which is formed by lava squeezing upward through a crack or a hole.

    stacked plates
    Plates form when lava drains from below a thin crust. The plates are dragged along by the last of the flow until one snags. All the other plates pile up behind the first.
    Photo courtesy of Rob Ratkwoski

    standing waves
    A stationary bump on the surface of a flow.

    Tess's bumps
    A hemi-spherical drop of lava that occasionally appears on a ceiling.

    tree molds
    A casting of a tree trunk, or branch, formed when lava floods around the tree.

    tube in tube
    A crust which forms within a tube divides the tube vertically thereby creating a tube within a tube.
    Photo courtesy of Rob Ratkwoski

    Cave Life

    This section illustrates the diversity of life forms found in Kazumura cave. This list is by no means complete.

    With a length of less than 1/32" (.794mm), this beetle is one of the smallest creatures found in the cave.

    book lice (psocid)
    Book lice normally live in leaf litter. This one was found on a pool of water next to a dead mosquito.

    cave slime
    Slime begins life as a spore. When the spore reaches a moist surface, it germinates into a single celled organism similar to an ameba. Slime eats bacteria. If food becomes scarce, individual slime cells come together and migrate. Migrating slime leaves behind visible tracks. To reproduce, the slime forms a fruiting stalk, which is similar to a mushroom, but without the cap.

    At least two species of cave adapted centipedes have been found in Kazumura Cave. Both seem to be fairly rare.
    Photographed on a pool of water.

    Cave crickets have antenna which can be up to five or six times their body length. The extended reach helps the cricket find food.

    deadly fungus
    Most fungi found underground grow on introduced foreign matter. This beautiful fungus is so toxic that any cave creature which considers it food will surely die.

    Cave earwigs are both hunters and scavengers.

    Two species of cave fly can by found in Kazumura.

    Hawaiian snake
    This snake like worm normally lives on the forest floor; but is occasionally found underground.

    Judy's freckles
    Freckles are found on cave floors and walls. They're the result of an introduced organism which turns the rock red. (Probably an iron fixing bacteria.)

    A liverwort is a plant similar to a moss which usually has flat leaves. They like deep shade, so they are often found inside cave entrances.

    The term microbe applies to any single celled organism. In Kazumura, microbial mats sporadically cover the walls and ceiling.

    According to the book "Hawaiian Insects and Their Kin" by F G Howarth and W P Mull, Kazumura's common millipede eats fungi, which may or may not be correct. These millipedes have been observed eating: the interior remains of other millipedes, their own skin that they just shed, and the remains of other dead creatures.
    Kazumura's common millipede
    Common millipede's apparent surface counterpart. Notice the dots on the near side.

    millipedes - other species
    Aside from Kazumura's common millipede (see previous entry), other adapted species can occasionally be found in the cave.

    mineral fixing bacteria
    A bacteria which leaves behind a mineral deposit is said to be mineral fixing. Barnacle like structures found in Kazumura are believed to be formed in this manner.

    Cave moths lay their eggs on ohia roots. The larva, which are carnivorous, patiently wait for a meal to come by. The cocoon is made from bits of ohia roots held together with silk.

    moth fly
    Moth flys have been found in other caves on the island. They eat bacteria. It is unclear if they are found in Kazumura as well.

    Mushrooms are the fruiting bodies of certain types of fungi. In Kazumura, mushrooms can occasionally be found growing on Ohia roots. These mushrooms look like tiny roots with caps.

    ohia roots
    The ohia tree is able to grow on barren lava. The tree's roots are so fine that they can grow through the pores in the rock. This allows the tree to tap into nutrients and water sources that other plants can't access. In time, leaves dropped by the ohia decay and produce soil. Underground, the roots provide various cave adapted creatures with food and a home.

    pill-bug / sow-bug / potato bug
    Sow-bug exoskeletons have been found in caves on the island. What is unclear is whether these creatures were cave adapted or just lost.

    plant hopper (oliarus polyphemus)
    Plant hoppers live on ohia roots and suck the sap. They build a cocoon around themselves for protection. Their tail is wax. If a predator attacks the plant hopper from behind, it gets a mouthful of wax and the plant hopper can possibly get away.

    Cave silverfish are elusive creatures which can rapidly disappear into small holes in the rock. For this reason they are seldom seen.

    small eye big eye blind cave spider
    The small eye big eye is a wolf spider with very delicate hairs on its legs. According to one source, these hairs allow the spider to feel the air movement of its prey. The small eye also uses a single strand of silk as a trip wire.

    spring tail
    Spring tails are insects that can propel themselves more than 200 times their body length. One species prefers to live on pools of water where organic matter collects. A much larger species was found by a dead worm.

    water spider
    This spider was spotted on the surface of a small pool. It is unclear if this is a known species.

    web building spiders
    Small spiders are found throughout the cave. Their primary food source is insects that fly into the cave and become trapped.

    Cave Archeology

    This section illustrates some of the many ways that ancient Hawaiians used lava tubes. This list is by no means complete.

    Growing a crop on barren lava is a challenge; but the Hawaiians did just that. The thin roof of shallow lava tubes occasionally drip water. If enough water drips, organic matter will rot. By placing organic matter under these drips the Hawaiians could grow a crop of sweet potatoes in a cave entrance.

    Different types of burials can be found in caves. In most cases, the dead were stripped of their flesh and the bones cleaned. The long bones and skull were placed in caves. The other bones were given to family members and possibly friends. It was believed that the spirit would come back and inhabit the bones on at least one special day each year. By having the bones of loved ones and ancestors with you, you could feel close to that person on that day.

    Occasionally, a whole skeleton is found. In these cases, the person knew death was near and found their own resting place. Sometimes their spouse would accompany them to the grave.

    commune with Pele
    There is a hula chant about a lava flow that was approaching Hilo. To stop the flow, the queen went into a lava tube to commune with Pele. The flow stopped.

    It was not all aloha between villages, they often fought. To defend your group, you might try hiding in a cave, but if you did, the entrance needed to be nearly impossible to find.

    Another possibility was to find a cave big enough for everyone, but with a small entrance. The entrance could be further reduced to allow only one attacker in at a time. In this case you would bludgeon or spear that attacker and plug the hole. The down side was that your enemies could smoke you out.

    A better solution involved finding a large cave with high ground. Build a rock wall on the edge of the high ground and stock the area behind the wall with rocks and spears. This gave you the high ground advantage.

    Heiau (a Hawaiian temple) were occasionally placed in cave entrances. The heiau associated with the "place of refuge" entry, is one such example.

    After Captain Cook left Hawaii, disease spread through the population. It has been said that caves were used as hospitals during the crisis.

    place of refuge
    In old Hawaii, anyone who violated a kapu (a law) would be killed for the violation. The only hope of survival was to make it to a place of refuge (a sanctuary).

    Refuges were sometimes placed in caves. In one instance, the offender would run into a specific cave entrance where a cleared trail led to a lava fall. If the offender wasn't killed by pursuers before reaching the fall, they would climb it. At the top was a small pile of rocks to be use for defense. If the offender could stop the pursuers using only those rocks, they could stay at the refuge heiau (temple) until things cooled off back at the village.

    navigational maps
    Occasionally, navigational maps are found in caves. Observed maps have been composed of roots, rocks and ti leaves. The roots are used to create a north-south / east-west grid. Rocks placed on this grid represent islands; and ti leaves placed around the rocks represents shallow water.

    In maps of the Hawaiian islands, only four rocks are used to represent the eight major islands. Kauai and Niihau are represented by one rock. Maui, Molokai, Lanai, and Kahoolawe are represented by another. The Big island and Oahu have their own rocks.

    Caves were used for shelter. The number of occupants living in a particular cave depended upon the size of the cave and the resources available in the area. The actual number of occupants could range from one individual to a whole village.

    water collection
    On most of Hawaii Island, there is little flowing surface water. To survive, Hawaiians placed gourds, coconut husks, bowls, or even canoes in caves to collect dripping water. The more water you could collect, the richer you were considered.

    Hawaii's Cave Law [5,6]

    Cave Ownership - Title to all mineral and metallic mines reserved to the State of Hawaii.

    Certain minerals form almost exclusively in lava tubes. This makes a lava tube a natural mine and therefore ownership falls to the State.

    Cave Features and Formations - It is unlawful to intentionally, knowingly, or recklessly damage, deface, or destroy any cave surface, formation or feature.

    Gates - It is unlawful to break, force, tamper with or otherwise disturb a gate to any cave.

    Signs - It is unlawful to remove, deface, or tamper with any sign stating that a cave is posted or citing cave law.

    Bones - It is unlawful to take, appropriate, excavate, injure, destroy, or alter any paleontological deposit.

    Dumping - It is unlawful to dispose of refuse, garbage, dead animals, sewage, litter, or toxic substances in any cave or cave entrance.

    Burning - It is unlawful to burn any substance in a cave or cave entrance as the smoke and gases can be harmful to naturally occurring organisms.

    Cave Life - It is unlawful to intentionally, knowingly, or recklessly remove, kill, or substantially harm any native or endemic organisms in a cave except as provided by a scientific permit obtained from the appropriate agency.

    Sale of Cave Items - It is unlawful to sell or offer for sale any portion of a cave surface or cave formation.

    Cave Tours - Commercial entry to caves shall be limited to operations in place at the time of the passage of this Act. No new operations may be established until the adoption of rules by the dept. to implement this section.

    Access - No person may enter a cave without the property owner's consent.

    Criminal Penalties

    Misdemeanor for violating this law:
    First offense - not less than $1000
    Subsequent offenses - Not less than $1500

    Intentional, knowing, or reckless damage, destruction, removal, taking, sale, or illegal possession of each specimen of cave resource shall be subject to a fine of not less than:
    $1000 for the first offense
    $1500 for any subsequent offenses with each day of continued violation considered a separate offense.

    Administrative fines
    First offense - up to $10,000
    Second offense - up to $15,000
    3rd and subsequent offenses - up to $30,000
    Research Ideas

    Many of the following questions were asked by cave visitors. These questions are presented here as possible ideas for research projects.

    How do lava blades form?

  • The following is known about lava blades.
  • - They form near skylights.
  • - Cold air entering the tube through the skylight causes a crust to form and thicken.
  • - As the crust thickens the tube's cross section is reduced.
  • - When the lava levels drop, hot air rising up the tube accelerates at the reduced cross section. This produces conditions similar to those existing in a jet engine or a rocket nozzle.
  • - The blades seem to form in places where the lava flow is moving faster.
  • - The turbulent flow caused by an increased flow speed would release gases from the lava.
  • - The surface of the blades often appear to be composed of small wind blown droplets of lava.

  • The unknowns are as follows.
  • - Does the wind sculpt the blades directly into a putty like surface?
  • - Do standing waves form on the flow surface? If so, does each wave contribute to its own blade?
  • Does the flow speed play a part in the formation of the blades?
  • - Do the escaping gases form bubbles which are large enough to throw small lava droplets into the gale force winds?
  • - Airborne droplets would slam into a surface and be immediately blown out. Are the eddy currents formed behind these imperfection the cause of the blades?
  • - How many of these factors are involved in the formation of the blades?
  • To accurately resolve this problem, a physical model is needed. There are too many variables and possible hidden factors for computer modeling. Lava blades form as a result of a fluid interaction and possibly oxidation. The only role heat plays in their formation is to provide a driving force for the air. In a physical model, an electric fan can perform this task. One fluid which may provide a fair representation of lava is wood workers glue. Its inexpensive, has a high viscosity, it doesn't solidify too fast or too slow, and its sticky.

    If your interested in this project you'll need to visit Kazumura.

    Are there older lava tubes in the walls of Kazumura?

    The lava that formed Kazumura, flowed long enough to create underground canyons. During this process, older lava tubes were occasionally intersected. In at least one location, a bulging wall is suspected of being an older tube. It would be interesting to know how often lava tubes intersect.

    Possible non destructive methods for penetrating the rock include sound and ground penetrating radar. To preserve the cave environment, any equipment used on site must be small enough to be easily packed and transported

    Do microbial mats on cave surfaces break down the rock?

    This question encompasses far more than one might think. For example, the ohia tree has the ability to grow on barren lava. It therefore must have some means of getting nutrients from the rock. It is known that the ohia gets nitrogen from a nitrogen fixing bacteria and in return gives away some of the sugar it would normally use to grow. Given the nature of this relationship, how many other organisms are needed for the tree to grow? Or does the tree secrete a compound that pulls the required nutrients from the rock?

    Another good question related to this is, how do these microbes colonize new lava flows? The new flows are sterile and heat radiating into the ground kills the organisms immediately below.

    How long does it take for an organism to lose its pigment after it enters the cave environment?

    Related questions.

  • - What causes a creature to enter a cave in the first place? Food is not generally abundant in caves. A creature having recessive genes for albinism can hide during the day and become nocturnal.
  • - Is the loss of pigmentation related to a genetic switch, or a body's attempt to conserve energy?
  • - If cave entry is accidental, what causes some organisms, like toads, to remain in entrances, while others become cave adapted?
  • Cave Bats live in caves and generally feed outside at night and yet they have pigmentation. Why is this?
  • How long does it take a cave adapted creature living near an entrance to get its pigment back?

    Related questions.

  • - It takes three generations for wild pigs to lose their tusks. It takes one generation for an escaped domesticated pig to grow the tusks back. Is it the same type of mechanism that would allow an organism to regain its pigment?
  • - If cave adapted organisms can regain their pigment, can they regrow eyes?
  • Why does the “Small eye Big eye blind cave spider” have hair which appears to be pigmented while the abdomen is albino?

  • How many species of cave adapted web building spiders are there?

    The web building spiders pictured in the Cave Life section appear to be different species. They were found about a 1/4 mile apart in Kazumura Cave.

    Are there any long term impacts to the cave environment from naturally introduced toxins?

    Rats and other larger creatures can occasionally become trapped in a cave. Their droppings can grow a deadly fungus. A short term effect of this introduced toxin is the death of any creature eating the dropping; but what are the long term effects?

    In one instance, a ring of about 20 dead millipedes was found around a single fungus infected dropping. Given the number of millipedes involved the population took a severe hit; but what of the scavengers that find the dead millipedes? Will they suffer the same fate, or will the fungus loose its toxicity in time? Do such toxins get carried away with the dripping water?

    What surface centipede did Kazumura's centipede descend from?

    Many cave creatures have surface cousins which look quite similar. This does not seem to be the case with the cave centipede. Surface centipedes are quite different.

    How close to a lava cave is it safe to build?

    To protect caves and land owners alike, practical guidelines related to minimum safe clearing distances from caves need to be established.

    Source Material

      1. DEVELOPMENT AND MORPHOLOGY OF KAZUMURA CAVE HAWAII by Kevin Allred and Carlene Allred, Journal of Cave and Karst Studies, 59(2): p67-80 (April 1997)
      2. KAZUMURA CAVE ATLAS, Hawaii Speleological Survey, (2002)
      3. UNDERSTANDING LAVA TUBES AND LAVA CAVES Second Edition by Harry Shick, Kazumura Cave Tours, (2012)
      4. PHOTO'S by Harry Shick and Rob Ratkowski
      5. Section 501-82 of the Hawaii Revised Statutes
      6. S.B. No. 2898