Glow worm cave, New Zealand

The Waitomo Glowworm Caves attraction is a cave at Waitomo on the North Island of New Zealand, known for its population ofglowworms, Arachnocampa luminosa. This species is found exclusively in New Zealand. They are around the size of an average mosquito. This cave is part of the Waitomo Caves system that includes the Ruakuri Cave and the Aranui Cave.

The attraction has a modern visitor centre at the entrance, largely designed in wood. There are organized tours that include a boat rideunder the glowworms.

History[edit]

The name "Waitomo" comes from the Māori words wai, water and tomo, hole or shaft. The local Māori people had known about the caves for quite some time before the local Māori Chief Tane Tinorau and an English surveyor, Fred Mace, did an extensive exploration in 1887.^{[citation needed]} Their exploration was conducted with candlelight on a raft going into the cave where the stream goes underground. This is now the exit for the cave. As they began their journey, they came across the Glowworm Grotto and were amazed by the twinkling glow coming from the ceiling. As they travelled further into the cave by poling themselves towards an embankment, they were also astounded by the limestoneformations. These formations surrounded them in all shapes and sizes.

They returned many times after and Chief Tane independently discovered the upper level entrance to the cave, which is now the current entrance. Tane Tinorau and his wife Huti, by 1889, had opened the cave to visitors and were leading groups for a small fee. The administration of the cave was taken over by the government in 1906 after there was an escalation in vandalism. In 1910, the Waitomo Caves Hotel was built to house the many visitors.

In 1989, the land and cave were returned to the descendants of Chief Tane Tinorau and Huti. They now receive a percentage of the cave’s revenue and are involved in the management and development of the cave. These descendants encompass many of the employees of the caves today.^[1]

Geology[edit]

Geological and volcanic activity has created around 300 known limestone caves in the Waitomo region over the last 30 million years.

The limestone formation in the Waitomo Glowworm Caves occurred when the region was still under the ocean about 30 million years ago.^[2] The limestone is composed of fossilized corals, seashells, fish skeletons, and many small marine organisms on the sea beds. Over millions of years, these fossilized rocks have been layered upon each other and compressed to create limestone and within the Waitomo region the limestone can be over 200 m thick.

The caves began to form when earth movement caused the hard limestone to bend and buckle under the ocean and rise above the sea floor. As the rock was exposed to air, it separated and created cracks and weaknesses that allowed for water to flow through them dissolving the limestone and over millions of years large caves were formed.

The stalactites, stalagmites, and other cave formations grew from water dripping from the ceiling or flowing over the walls and leaving behind limestone deposits. The stalagmites form upward from the floor while the stalactites form from the ceiling. When these formations connect they are called pillars or columns and if they twist around each other they are called helicti. These cave decorations take millions of years to form given that the average stalactite grows one cubic centimetre every 100 years.