Kaneana EarthCache

Kaneana is a sacred ana (cave) that ancient Hawaiians named after Kane, the god of creation. From inside the depth of Kaneana, symbolic of the earth goddess's womb, mankind emerged and his existence spread throughout the Waianae Coast. The souls of those who passed on go to Kalae O Kala'au (Ka'ena Point). From there souls ascend to Po, the realm of ancestral spirits, completing the cycle of life.
In ancient times, entry into Kaneana was kapu (forbidden) for this was the home of Nanaue, the Shark Man of Kaneana.

Located on the Leeward (west) Coast of Oahu between Ohikilolo and Makua Valley sits Kaneana, more commonly known as Makua Cave. Kaneana is believed to be approximately 150,000 years old and more than 450 feet deep. Studies suggest that the volcanic rock was eroded by the sea to form a cave out of an existing lava tube when sea levels where much higher than they are today.

A sea cave is also known as a littoral cave. They are usually formed by the wave action of the sea eroding the land. The larger caves are formed in a type of volcanic rock called basalt. They form in areas of weakness such as a fault line.

Littoral caves may be found in a wide variety of host rocks, ranging from sedimentary to metamorphic to igneous, but caves in the latter tend to be larger due to the greater strength of the host rock. To form a sea cave, the host rock must first contain a weak zone. In metamorphic or igneous rock, this is typically either a fault or a dike. In sedimentary rocks, this may be a bedding-plane parting or a contact between layers of different hardness. The latter may also occur in igneous rocks, where waves have attacked the contact between the andesitic basalt and the agglomerate. Erosion is ongoing anywhere that waves batter rocky coasts, but where sea cliffs contain zones of weakness, rock is removed faster. As the sea reaches into the fissures thus formed, they begin to widen and deepen due to the tremendous force exerted within a confined space, not only by direct action of the surf and any rock particles that it bears, but also by compression of air within.

Lava tubes are a type of lava cave formed when an active low-viscosity lava flow develops a continuous and hard crust, which thickens and forms a roof above the still-flowing lava stream. Tubes form in one of two ways: by the crusting over of lava channels, and from pahoehoe flows where the lava is moving under the surface.

Lava usually leaves the point of eruption in channels. These channels tend to stay very hot as their surroundings cool. This means they slowly develop walls around them as the surrounding lava cools and/or as the channel melts its way deeper. These channels can get deep enough to crust over, forming an insulating tube that keeps the lava molten and serves as a conduit for the flowing lava.

Further away from the eruption point, lava can flow in an unchanneled, fanlike manner as it leaves its source, which is usually another lava tube leading back to the eruption point. Called pahoehoe flows, these areas of surface-moving lava cool, forming either a smooth or rough, ropy surface. The lava continues to flow this way until it begins to block its source. At this point, the subsurface lava is still hot enough to break out at a point, and from this point the lava begins as a new "source". Lava flows from the previous source to this breakout point as the surrounding lava of the pahoehoe flow cools. This forms an underground channel that becomes a lava tube.