Five Volcanoes !

All Hawaiians know the Big Island was created by the commingling lava flows from five immense volcanoes, but most visitors know only two – i.e., Mauna Loa and Mauna Kea.  And, somewhat uniquely, the volcanoes of Hawaii are not where plates meet, but actually thousands of miles from the nearest plate boundary in what is known as a “hot-spot” in the Pacific Plate.  Also, Hawaii’s volcanoes are not the type like Mt. St. Helens or Mt. Etna that can have explosive eruptions; they simply release flows of relatively fluid lava.

http://hvo.wr.usgs.gov/kilauea/

Currently there are two volcanoes on the Big Island classified as active:

1.   Kilauea, actively erupting for almost the past 30 years is the world’s most active volcano.  It has been spewing lava continuously since January 1983.   Kilauea nestles into the side of Mauna Loa and was once considered a part of Mauna Loa, but subsequent research showed that it has its own “magma-plumbing system.”  http://hawaii.aloha-hawaii.com/hawaii/big+island+volcanoes/

Located in Volcanoes National Park near the caldera of Kilauea is the “fire pit,” which is known as Halemaumau (“House of Everlasting Fire”).  Halemaumau at times has a contained lake of boiling lava. The pit is enlarged periodically by steam blasts and collapsing walls. Typical eruptions consist of lava flows forming lava lakes in Halemaumau or elsewhere on the caldera through fissures and rift zones.  Volcanoes National Park is actually Hawaii’s most visited tourist attraction, with nearly 9,000 daily visitors coming to the park. http://www.hawaiilogue.com/active-volcanoes-in-hawaii.html

Pele, the Hawaiian Volcano Goddess, is said to live within the Halemaumau firepit.

2.   Mauna Loa (“Long Mountain”), which last erupted in 1984 is the world’s largest volcano. It is also considered one of the most active volcanoes, having erupted 33 times since 1843.

Both of these active Hawaiian volcanoes share the Hawaiian hot spot, but retain unique volcanic histories and compositions.

And three volcanoes on Hawaii are generally classified as dormant:

1.   Kohala, the oldest, which is believed to have emerged from the sea more than 500,000 years ago.

2.   Hualalai, with six different vents that spewed lava, two of which produced lava flows that reached the ocean. The Kona International Airport is build atop the larger of the two flows. It last erupted in 1801, but some still consider it still “active,” which would be a major problem for the population center around Kona-Kohala.

3.   Mauna Kea (“White Mountain”), reaching 13,796 feet above sea level is the world’s tallest mountain (measured from the floor of the ocean to its summit) which last erupted about 4,000 years ago.  It is often snow covered in winter.  It is also the site of 13 astronomical observatories and is expected to be home to what will be the world’s largest telescope, the Thirty Meter Telescope.

       http://www.soest.hawaii.edu/GG/HCV/haw_formation.html  //hawaii.aloha-hawaii.com/hawaii/big+island+volcanoes/

Since the vast majority of earthquakes and volcanic eruptions occur near plate boundaries, how did the Hawaiian Islands which are entirely of volcanic origin, form in the middle of the Pacific Ocean almost 2,000 miles from the nearest plate boundary?

“J. Tuzo Wilson came up with the Hotspot Theory in 1963. According to his theory, the Hawaiian Island chain resulted from the Pacific Plate moving over a deep, stationary hotspot in the mantle, located beneath the present-day position of the Island of Hawaii. Heat from this hotspot produced a persistent source of magma by partly melting the overriding Pacific Plate. The magma then rises through the mantle and crust to erupt onto the seafloor, forming an active seamount.

Over time, countless eruptions cause the seamount to grow until it finally emerges above sea level to form an island volcano. As the plate movement carries the island beyond the hotspot, the magma source is cutoff, and volcanism ceases. As one island becomes extinct another develops over the hotspot.”  http://www.pdc.org/iweb/volcano_history.jsp

In fact right now a young submarine volcano called Loihi (“Long”) is growing about 20 miles south of the Big Island.  Its ascending summit is currently 3,000 feet below the ocean surface.  http://www.bestplaceshawaii.com/island_insights/bigisland/volcanoes.html

When most people envision a volcano, they think of a tall and cone shaped volcano (think Mount Hood outside of Portland, Oregon). These strato volcanoes tend to have dramatic and explosive eruptions (think Mount Saint Helens).

The five volcanoes of the Big Island are shield volcanoes, which are long and broad and have gently sloping hills.  Shield volcanoes’ lava has a lower viscosity, meaning that the lava is thinner and more fluid.  Because of the fluidity of the lava, major explosive eruptions generally do not occur.  This is why the almost constant flowing lava of Kilauea can be approached and seen by visitors to Volcanoes National park. http://www.hawaiilogue.com/active-volcanoes-in-hawaii.html

All the photos in this post are by Bryan Lowry, are © protected and usage requires his permission.  Please visit Bryan‘s website to see the vast collection of images by this award winning photographer whose photos have also appeared in National Geographic (http://lavapix.com). Significantly, 20% of Bryan’s website sales profits go to Easter Seals Hawaii on the Big Island.

Big Island to Maui -- Crossing the Channel

The Alenuihaha Channel (or the “I'll-end-you, ha-ha” channel), between the islands of Hawaii and Maui, is 26 miles wide in its narrowest part and has sometimes been referred to as the most dangerous channel crossing in the world.

Roughly translated, Alenuihaha means “of very large, trough-like waves.” Like most Hawaiian words or phrases there can be several interpretations. Another one breaks down the channel’s name into ale meaning to swallow or engulf, nui meaning large or great, and haha meaning to breathe hard or pant. And a third translation suggests Alenuihaha is "the angry woman.”

The U.S. Coast Guard’s view is that the “channel is generally regarded as one of the most treacherous channels in the world because of strong winds and high seas.” Basically channel travelers are getting blasted by the venturi effect between two of the world's tallest mountains – on Maui, Haleakala and on Hawaii, Mauna Kea. Experts say all of the ocean has to funnel in between the two islands and this creates a pretty strong current. “It’s like the whole Pacific Ocean trying to squeeze through something.” Hawaii Kayaker

Oh, and the channel is also shark infested.

Penny Palfrey

In fact until just last year, there had only been one successful solo swim of the channel ever from the Big Island to Maui. Then, in March 2009, the Australian Penny Palfrey became the second person, and first female, to cross the channel. It took her 14 hours and 51 minutes. And she had to deal with occasional 20-foot ocean swells where her crew lost sight of her. Penny Palfrey

Then in quick succession in September 2009, Linda Kaiser of Hawaii became the third swimmer, at age 59, to do the channel -- in 17 hours. Also, Linda is the only person in the world to swim all eight Hawai’i channels

The first to accomplish this feat was Dr. Harry Huffaker in either 1969 or 1970 (“within a mile of finishing”) according to Hawaiʻi Sports: History, Facts, and Statistics by Dan Cisco, with a time of 20 hours and eight minutes. Not sure why the last mile does not count in solo swimming, but Dr. Huffaker is clearly considered the first to have swum the channel.

Mike Spalding, who was inducted into the Hawaii Swimming Hall of Fame in 2008 for his seven successful channel swims between Hawaiian Islands, said he has only one remaining, “the hardest one,” the 30-mile Alenuihaha channel.

Cookie Cutter Shark Teeth

His first attempt at age 61, was like Penny Palfrey’s in March 2009, but it lasted only 4-1/2 hours when he was bitten by a cookie-cutter shark. It left a three-inch diameter, one-inch deep would on his left leg. This species of shark grows to about 20 inches in length and takes melon-ball sized chunks of flesh from its prey. Spalding said. “I’ll be back in the hunt, back trying to train for the channel again. . . . I’m looking forward to the next time I get out there and finish this channel.” Maui News

An article about the channel in Sports Illustrated back in 1973 (Carlton Fisk was young) had the following title and teaser:

“Olly As In Jolly, Haha As In Crutch”

“The Alenuihaha Channel was no laughing matter; it was miles of thrashing current and biting wind that tossed the ocean racers. And it was only the beginning of the first around-a-state contest ever held.”

The article by Richard W. Johnston went on to say that yachtsmen would do well to memorize the name: “olly as in jolly, nooey as in hooey, and haha as in crutch.” I am certain that the haha part is not haha funny but probably more like haha sad. So the “crutch” part is either “funny as a rubber crutch,” or some nautical term, insider-joke that misses me totally. Richard W. Johnston

If anyone reading this knows, please leave a comment.

Aloha

"Time and Tide Wait for No Man"

Continuing the topic of tides, we now know why there are two high tides and two low tides at most places on the earth daily (see “Swimming with the Tide in Hawaii”). How high or low the tides are depends on the relative location of the earth, moon and sun.

Spring Tides

When the moon is full or new, the gravitational pull of the moon and sun are combined. The combined gravitational attraction of the two bodies produces a very strong tide that “springs forth” onto the coast, and thus is called a spring tide. (Spring tides have nothing to do with the season of the spring.) They occur when the Earth, the Sun, and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon.

Redfishpro.org

Neap Tides

During the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons. http://home.hiwaay.net/~krcool/Astro/moon/moontides/

Redfishpro.org

Tide Charts

http://freetidetables.com/?tides_data%5bttiq%5d=-16,2

Tide charts show a tremendous amount of information (please follow link to see larger size). They show the times of sunrise, sunset, moonrise and moonset. They also show the phase of the moon and the times of the two high and two low tides each day. And the vertical axis shows the height or depth of the tide in feet as a variance to the Mean Lower Low Water (MLLW) level – defined in the last post.

You can see for example that in Hilo the high tide this week will be on Saturday with the new moon at about three feet above MLLW and occurring at 15:55 (3:55pm), and lowest tide that day will be about 0.7 feet below MLLW at 8:30am. And these are spring tides because the sun, moon and earth are in a straight line with each other.

Four feet is about the maximum variance of the tides at Hilo which isn’t much as you can see by the two photos below taken from our home here.

Low Tide

High Tide

The highest tides in the world at over 50 feet (!) are at the Bay of Fundy in Nova Scotia, Canada. The Bay of Fundy even has an interactive site where you can see the impact of such tides at http://www.bayoffundytourism.com/.