Cave Rock - Tuawera (Canterbury) EarthCache
Cave Rock - Tuawera (Canterbury)
-
Difficulty:
-
-
Terrain:
-
Size: 
(other)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
A Earthcache at Cave Rock, Sumner.
Cave Rock is an unusual volcanic formation on Sumner Beach. For many years it has provided a playground for Christchurch children visiting the beach. Maori call the rock Tuawera, and say that it represents the carcass of a legendary whale washed up on the beach. Tuawera is the Maori name for the large imposing rock that sprawls silently on the beach at Sumner. Tuawera fuguratively means "cut down as if by fire" and refers to the many people who died from eating the flesh of a great whale that was stranded on the shore.It is said that the rock represents the carcass of that deadly whale which was beached by means of black magic.
A sea cave, also known as a littoral cave, is a type of cave formed primarily by the wave action of the sea.
The primary process involved is erosion. Sea caves are found throughout the world, actively forming along present coastlines and as relict sea caves on former coastlines. In places like Thailand's Phang Nga Bay, solutional caves have been flooded by the rising sea and are now subject to littoral erosion.
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.
In order to form a sea cave, the host rock must first contain a zone of relative weakness. In metamorphic or igneous rock, this is typically either a fault as in the caves of the Channel Islands of California, or a dyke as in the large sea caves of Kauai, Hawaii’s Na Pali Coast. 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, such as in the caves on Santa Cruz Island, California, where waves have attacked the contact between the andesitic basalt and the agglomerate.
The driving force in littoral cave development is wave action. Erosion is ongoing anywhere that waves batter rocky coasts, but where sea cliffs contain zones of weakness, rock is removed at a greater rate along these zones. 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. Blowholes (partially submerged caves that eject large sprays of sea water as waves retreat and allow rapid re-expansion of air compressed within), attest to this process. Adding to the hydraulic power of the waves is the abrasive force of suspended sand and rock. Most sea-cave walls are irregular and chunky, reflecting an erosional process where the rock is fractured piece by piece.
The Story of Tuawera
Turaki Po, a chief of Opawaho sought Hineao, a daughter of Te Ake of Akaroa for a wife. She spurned his advances so Turaki Po cast a spell of death upon her.
In revenge Te Ake her father went to the hill overlooking Sumner and sent forth mighty karakia against Turaki Po and his people.
In answer to his prayers a whale was stranded on the shore which the people of Turaki Po eagerly cut up and feasted upon. Those who ate the whale fell asleep and subsequently died.
Turaki Po, feeling that the stranded whale was the result of makutu (black magic), did not partake with his people. However, later, having few followers left to help him he was duly slain by Te Ake’s party.
You can see Cave Rock on this webcam here:Surf Cam
I suggest visiting The site at anytime, though an hour or two out from high tide may make it tricky. Tide times for Sumner can be found here:Tides
To log this EarthCache, you must do the following and email us the results. You can go ahead and log your find, (ie. you don't need to wait for permission) but if we don’t think you have honestly completed the required tasks we will delete your log (after emailing you first of course):
1) Go to the cache cords and estimate visually the width of the mouth of the Cave, at ground level.Email me this info, don't post in your log.
2)Tell me what side of the Rock has recieved the most damage after the earthquakes, discribe what you see.
3)Take a photo of the Rock and upload with your online log
4) Estimate the height of the rock, and its width.
5)Tell me what type of rock Cave Rock is made up from
Please email me this info, please DONOT post it with your log.
Please take care around the area, and keep an eye on any little ones with you.
Additional Hints
(No hints available.)