The Volcanic Landmarks of Oahu, Hawaii – The Conclusion

Hanauma Crater

Hanauma Bay. Image by ErgoSum88 (Wikipedia – public domain)

The Hanauma Crater was created during the Honolulu volcano series. The volcanic vents that formed Hanauma Crater opened on the seafloor about 32,000 years ago. Upwelling magma vaporized the ocean water and steam explosions atomized the magma into fine ash. The explosions built cones of ash, which solidified into tuff. The eruptions shattered the coral reef and basalt sea floor and scattered pieces that are now embedded in the tuff. Wave erosion eventually cut through the low, southeast wall of the crater, forming the current bay.

The Hawaiian word hana means “bay”; the word uma means “curved.” Thus, one translation of Hanauma is “curved bay.” Uma also means “stern of a canoe.”  It is unlikely any villages were built at Hanauma in ancient times because of its hot climate, low rainfall, nutrient-poor soil and lack of fresh water. But the Hawaiians definitely fished there.  The bay was used as a recreational area by the Hawaiian nobility, who fished, entertained visitors, and sponsored games there.   It was also used as a layover and as a navigational lookout point when the waters between Oahu and Molokai were too rough for traveling in their canoes.

Bernice Pauahi Bishop was a Hawaiian princess, the last direct descendant of the Royal House of Kamehameha.  In 1857 she inherited a family estate totaling 16,011 acres.  In 1883 she inherited another 353,000 acres from her cousin, Ruth Keʻelikolani, the royal governess of the Islands.  Bernice was instantly the largest landowner in the Islands, in personal possession of about 9 percent of the Hawaiian landmass.  In 1928, the City and County of Honolulu established Koko Head Regional Park which encompassed Koko Head, Hanauma Bay, and Koko Crater by buying it for one dollar from the estate of Bernice Pauahi Bishop. A deed restriction limited its use to public parks and rights of way.

In the 1930s the road along Hanauma Bay’s corner of Oahu was paved and a few other amenities provided that made it easier to visit the beach and reef. After the 1941 attack on Pearl Harbor, barbed wire was placed at the beach and a bunker was constructed for use by sentries. The Bay area reopened after the war and became even more visitor friendly after blasting in the reef for a transoceanic cable provided room for swimming.  In 1967 Hanauma Bay was designated a Marine Protected Area by the state division of Fish and Game.  Everything became protected, from the fish to the reef, to the sand itself. A volunteer group set up a booth at the beach and began teaching visitors about conservation of the reef and fish who lived there. I find this a real oxymoron because the next thing that happened came about in the 1970’s.  The City cleared more area in the reef for swimming, made an additional parking lot, and shipped in white sand from the North Shore, leaving Hanauma Bay increasingly more attractive to visitors.  The white sand really stands out in pictures because the bay has natural green sand from the abundance of Olivine.  By the late 1980s tourists were brought in by the busloads, sometimes as many as 13,000 visitors in one day.  These crowds stirred up sediment, disturbed and trampled the coral and algae, dropped trash, fed the fish and left a slick of suntan lotion on the bay’s surface.  Consequently, the beautiful multicolored coral reef closest to the beach died; only its blackened skeleton is visible today.

Fortunately things started to change in the 1990’s.  Commercial filming was banned, beach access was limited to full capacity of the parking lot and a fee was levied to non-residents.  In August 2002, the Marine Education Center was opened at the entrance to the bay, where still today new visitors must watch a short film and receive instruction about conservation of the Bay’s resources. Upon watching the film, visitors are allowed to sign a form and skip any subsequent film if they should return within the following 365 days.  Today Hanauma Bay sees an average of 3000 visitors a day, or around a million visitors a year. The majority are tourists.  The bay is closed to tourists on Tuesdays in order to allow the fish a day of feeding without interruption by swimmers.

Hanauma Bay. Image from http://www.aloha-hawaii.com/oahu/beaches/hanauma-bay/

One of the danger spots in the bay is the Cable Channel, a small channel on the west side of the reef that was dredged in the 1950s to receive a trans-Pacific telephone cable. Strong rip currents may run through this channel and carry swimmers and snorkelers beyond the reef into the outer bay. The left point of the bay is called Palea, “brushed aside”, and the right point is Pai’olu’olu, “lift gently”. On each side of the bay a wave-cut terrace a few feet above sea level provides pedestrian access to each point. The terrace to Pai’olu’olu Point ends in a rocky cove called the Witches’ Brew. The prevailing trade winds push swells and debris into the cove, a natural catch basin, resulting in the name Witches’ Brew. The terrace on the opposite side of the bay, heading out to Palea Point, ends at an inlet called the Toilet Bowl. At the head of the inlet a small pool is separated from the sea by a natural rock wall. Swells that surge into the inlet cause the water in the pool to rise and fall like the flushing and filling of a toilet bowl. It has been closed due to injuries suffered by visitors. This video is really bad parenting, but shows the Toilet Bowl in action and you can really see the olivine in the rock.

This website from the University of Hawaii Education Program has some nice, short videos of the geology of Hanauma Bay. http://hbep.seagrant.soest.hawaii.edu/hanauma-geology

Koko Crater

Koko Crater, Hanauma Bay and Hawaii Kai. Image from Wikipedia (by Mbz1, CC-BY-SA-2.5).

 

Koko Crater can be seen directly north of Hanauma Bay.  It was created about 10,000 years ago during the Honolulu Volcano Series and is the tallest tuff cone on Oahu.  It was originally named “Kohelepelepe” meaning “traveling vagina” in Hawaiian.  Koko Crater is 1,208 feet (368.2 meters) with an opening on one side, hence its name.   Koko’s crater is 200 acres.  Also like Diamond Head and The Punchbowl, it had a military presence during World War II.  There is a bunker at the summit and was used as a radar installation.  A rail tram was installed to move men and equipment up and down the mountain.

 

Person crossing a natural arch at Koko crater. Image from http://www.unrealhawaii.com/2013/03/koko-crater-arch/ ( CC-BY-NC-ND 3.0)

Image from http://www.crazyintherain.com/koko-crater-railway-trail-honolulu-hawaii/

Koko Crater is accessible.  You can drive to the parking lot by the Botanical Gardens and walk in. Koko Crater is also a popular hiking destination, but it is not for the faint of heart or the less physically able. You can hike the old fashioned way.

Or you can do it this way using the old tram rail, straight up to the top. Parts of this are in very bad condition.

 

In 1958, the Department of Parks and Recreation set aside for development 60 acres of the inner slopes and basin of Koko Crater for a botanical garden. This garden focuses on the cultivation of rare and endangered dryland plants.  Xeriscape concepts (reduction or elimination of supplemental water) are used to transform this dry landscape into a garden where plants suitable to desert-like conditions can flourish.  The gardens have been subdivided into four major geographic sectors: Hawaii, the Americas, Madagascar and Africa.

Adjacent to the Botanical Gardens is the equestrian center, Koko Crater Stables.  It was constructed in 1960 and encompasses 10 acres.  The stables offer lessons, trail riding, horsemanship skills and a summer camp for kids.

Image from http://sparks-hawaii.blogspot.de/2006_05_01_archive.html

Mānana Island

Mānana Island, Oahu, Hawaii. Photo D Ramey Logan 1 (Wikipedia, CC-BY-SA 3.0).

The final volcanic landmark of Oahu is Manana Island, the northeast end of the rift.  In the Hawaiian language, mānana means “buoyant”. The islet is commonly referred to as Rabbit Island, because its shape as seen from the nearby Oahu shore looks something like a rabbit’s head and because it was once inhabited by introduced rabbits. The rabbit colony was established by John Adams Cummins in the 1880s when he ran the nearby Waimānalo plantation. The rabbits were eradicated about a hundred years later because they were destroying the native ecosystem, an important seabird breeding area.  Mānana is a tuff cone with two vents. The highest point on the islet rises to 361 ft (110 m). The island is 2,319 ft (707 m) long and 2,147 ft (654 m) wide and has an area of about 63 acres.

Today Mānana Island is a State Seabird Sanctuary – home to Wedge-tailed Shearwaters, Sooty Terns, Brown Noddys, Bulwer’s Petrels, and Red-tailed Tropicbirds, and numerous Hawaiian Monk Seals. It is illegal to land on the islet without permission from the Hawaii Department of Land and Natural Resources.

I hope you all enjoyed this series.  Doing the research was very interesting for me.  A question that came up previously was why some of the pictures of the volcanoes in this series are so green and others brown.  I learned while researching this post that it is seasonal.  The winter is the rainy season when everything turns that lush green.  During the summer, it becomes very dry and everything turns yellow or brown.  For a Midwesterner like me, January in Hawaii would sure beat cleaning 10 inches of snow off my car to go to work!

Bobbi

 

References:

http://en.wikipedia.org/wiki/M%C4%81nana

http://en.wikipedia.org/wiki/Hanauma_Bay

http://archives.starbulletin.com/2007/08/05/travel/tsutsumi.html

http://www.philanthropyroundtable.org/almanac/hall_of_fame/bernice_pauahi_bishop

http://www.summitpost.org/hanauma-bay/573956

http://oceansafety.ancl.hawaii.edu/v/2.0/?i=oahu&shid=4&bch=hanauma

http://www.city-data.com/articles/Koko-Crater-Botanical-Garden-Honolulu.html

http://hawaiianforest.com/geological-features-of-koko-crater

 

And here again Matt´s Friday riddles! This time look for volcanoes and a geology term. 

1) Land of these: Image. Two answers: Buckland volcano in Queensland, Australia and…, Sissel, 2 points. 1 bonus point for inannamoon667 for finding the name “Buckland”. 

2) Home of a famous husky and a natural sauna. Clue: Known for its wines, it was once captured with a corkscrew. Answer: Pantelleria. Operation Husky, the allied invasion of Sicily during WWII, was based there. There is also a natural sauna, which you can visit, that is said to be the love nest of Calypso and Ulysses. The allied operation to capture this island during WWII was called Operation Corkscrew. Inannamoon667, 1 point. 

3) The light burns forever on the nation’s highest peak. Answer: Mt Aragat, Armenia’s highest mountain.  St. Gregory the Illuminator brought Christianity to Armenia, and supposedly during one of his prayers at this mountain, a lantern that burns forever appeared; supposedly it is still there, but visible only to those pure of heart. Sissel, 2 points. 

4) This faction fights on the side of water. Answer: Liquefaction, Sissel, 2 points. 

5)  I was not defeated by Hernando de Soto, and I am not a volcano… I am a piece of one.  Answer: Tuscaloosa seamount, a chunk of Oahu that fell off in a giant landslide, with a tsunami at least 100 meters high! Tuscaloosa was a native chief who battled de Soto, and for whom the city in Alabama is named. Inannamoon667, 2 points. 

Score board:

9 Sissel
5 KarenZ
5 Inannamoon667
2 Dinojura44
4 Bobbi
1 RenatoRio
1 Talla

 

 

MATT