Thursday, July 11, 2013
|There is a picture of the author half-naked and relishing in an even more prominent vent, but I figured that’d be too steamy for this blog.|
|She takes the steam like a champ|
|Source: Hawaii Volcano Observatory, USGS – Retrived 7/16/2013 from Wikimedia Commons|
|Satellite shot of Kilauea on January 28, 2012 – Retrieved from NASA 7/16/13|
There are several things that stand out in this picture. So let’s get to it.
1.) The Halema’uma’u Crater
See that miniature crater from which steam is erupting within the larger Kilauea caldera? This is known as the Halema’uma’u Crater and is the current ‘eruptive center within the eruptive center.’ It has constantly been erupting a cloud of steam, sulfur dioxide, and other volcanic gasses since at least 1983.
And yes, there is the famed “hot lava” within Halema’uma’u. I came to Hawaii when I was 5, and when it turned out that I couldn’t see any hot lava, I had an extraordinarily large temper-tantrum that may very well have been mistaken for a high pitched eruption from within the crater. When I was young, I was obsessed with volcanoes. You think I’m obsessed with weather now? This is NOTHING compared to my preschool through 1st grade infatuation with geology, and, in particular, volcanology. Although atmospheric science has taken the top spot, it is followed closely by volcanology and oceanography, with women a distant 4th behind.
You couldn’t see the lava from where we were standing, so here’s a picture taken at night that shows the lava lake glowing below the crater. Parts of the park within the general caldera were closed due to an abnormally high risk of death due to an eruption of lava.
|Taken 3/22/13 at 10:10:35 (after dark) by Wikimedia contributor TimBray – Retrieved 7/16/13|
If you want a view of what’s happening inside the crater, check out this cam below. It is simply extraordinary.
In fact, the whole USGS Hawaiian Volcano Observatory website is awesome; check it out here:
2.) Kilauea Iki
The satellite picture shows two additional craters outside of the larger caldera. I don’t know anything about the smaller one, but the larger one is called Kilauea Iki. Kilauea Iki erupted in 1959 and has not had significant volcanic activity since, but for November 14 to December 20 of that year, Kilauea Iki was extremely active and put on some fantastic shows. The picture below is a “lava lake” inside Kilauea Iki. These lakes are common throughout the region and are the reason why the surfaces of these craters are so flat. The most expansive example of this in Hawai’i is the entire Kilauea caldera, but they can be found in other places throughout the island as well. There may even be some remnant lava lakes on Maui, Oahu, or Kauai, but I have no clue. However, they probably had lava lakes on them when they were under the current Hawaiian hotspot.
|Kilauea Iki filling with lava on November 14, 1959 – Retrieved from USGS on 7/16/13|
There were also some incredibly strong lava fountains from Kilauea Iki. A lava fountain is exactly what it sounds like; a fountain of lava. Imagine Drumheller Fountain at the UW, but instead of E. Coli with a little bit of water being shot up into the air, pure molten rock is. Some of these lava fountains were incredibly high, reaching 1,900 feet above their eruptive center. I don’t think there would be any geese defecating in the liquid in an environment like this.
|A lava fountain on Kilauea Iki on December 12, 1959 at 7:00 A.M. Retrieved from USGS on 7/16/13|
There were 17 separate eruptions in the 10/14 – 12/20 time frame. The first one began when the south wall of the mountain ripped open, and a “curtain of lava” a half mile wide flew into the crater. Kilauea Iki had erupted 90 years before, so a crater was already formed. With each successive eruption, the lava lake rose and rose, and with lava surging out the vent, huge waves of molten rock surged through the crater like waves in a nasty Columbia Bar crossing. The crater, which was 800 feet deep, was filled halfway with lava.
I’ll just stop and let that thought percolate through your mind for a bit.
The eruption finally ended when the lake rose high enough to drown the vent from which the lava was outpouring. The lava drained back down the vent but left behind a 50-foot “bathtub ring” of dark rock as evidence.
I took some pictures of the crater, and I have posted them below.
|Overlooking the crater from a trail we hiked around the rim of it|
|A steam vent of sorts inside the crater|
This was one of the most awe-inspiring eruptions ever recorded. As USGS scientist Don Richter (hint: there’s a scale named after him) said, “Our senses were overwhelmed by the eruption – we could see it, feel it, hear it, smell it.” The eruptions of Pinatubo and Mt. St. Helens may be more explosive and dramatic, but take a moment and imagine yourself staring at a fountain of lava over three times the height of the Space Needle. There is a mesmerizing component that these relatively gentle shield volcanoes have over catastrophic eruptions from stratovolcanoes.
3.) Different Rock Colors Within the Caldera
If you look inside the Kilauea caldera, you can see specific areas that are darker or lighter than others. I don’t know much about the origin or formation of these different colors, but if I had to guess, I would hypothesize that they were created by different lava flows originating from different areas at different times. The problem with that theory is that the surface of the caldera looks the same; there doesn’t look to be any overlying flows. Another theory which I think would be more plausible is that they were all part of the same lava lake at one time, but they had different characteristics and did not mix. Of course, the problem with that theory is that the transitions are pretty sharp, so there would have to be essentially no mixing of any of the lava, which, as a liquid substance, might not be very plausible. Lava is very viscous though, so it is quite possible that different lavas don’t mix that well.
This topic of lava flows leads me on to another very important subject (which is accordingly named)…
The Different Types of Lava Flows
I’m sure there are many different types of flows. One-flow, two-flow, red-flow, blue-flow. But for simplicity, we are going to focus on two types of flows: A’a and Pahoehoe
I hope you haven’t had trouble understanding anything I’ve talked about. But if you only come away with this blog from one thing, it will be the difference between a’a and pahoehoe.
Short answer: Don’t cross a’a barefoot
|Pahoehoe is in the foreground, A’a from a January 1974 lava flow is in the background|
Pahoehoe lava has a smooth surface texture, not unlike that of a pan of chocolate brownies. Additionally, they have little textures on them that provide a glimpse into how the lava cooled into solid basalt. Check out the pictures I took at the end of Chain of Craters road by the ocean.
A’a lava has an extremely rough surface, and it tends to remind me of the giant stones often around quarries, but only sharper and more numerous. Some a’a lava that I found had these incredible colors on the outside, with lots of blue/grey and copper-colored reflective material surrounding the rock. I don’t know what this is or how it was formed, but it sure is fascinating. The second a’a picture of a singular rock with an a’a background shows this well.
There are several differences in the way these two types of lava form. Pahoehoe tends to form in an eruption with a low rate of effusion (amount of lava discharged per unit time) while the opposite is true for a’a. Pahoehoe flows are more fluid and can spread across different parts of a landscape, but an a’a flow acts like a bulldozer and obliterates everything in its path. Pahoehoe flows can turn to a’a flows when there is a change in conditions or the pahoehoe simply loses heat and gas as it travels further from the vent from which it came, but it is hard for a’a to transition to pahoehoe.
Pahoehoe and a’a flows often come from the same eruption and there is no difference in chemical composition between them. This shows that the mechanism that determines whether the lava is a’a or pahoehoe is related to the physical conditions that the lava travels in rather tan the chemical composition itself.
It’s getting kind of late here… 5 P.M. with essentially no breaks, but I’ll try and wrap it up.
The steam vents were cool, but they could not compare to Sulfur Banks, a location nearby where sulfur crystals could be found. There were a host of gasses that were emitted from Sulfur Banks, including sulfur dioxide and hydrogen sulfide. These specific gases react with each other to create pure sulfur and water, and this sulfur manifests itself in these stunningly gorgeous yellow crystals. Don’t touch them though… they are fragile and coated with sulfuric acid. These crystals were known as kukaepele, or the waste of Pele. I wonder why…
They sure don’t look like waste though, even if they may smell like it. Take a look at some of the pictures I took of the banks. They are absolutely stunning!
|Some individual sulfur crystals|
|The banks as a whole|
These banks were formed when Kilauea’s summit collapsed 500 years ago. The summit collapse occurred because as the mountain continued to erupt, the magma reservoir under the mountain was gradually emptied. Eventually, the pressure upwards from the magma chamber to support the summit could not support the downward force of gravity, and the summit collapsed into a caldera. The collapse didn’t occur as one giant drop throughout the mountain… there was a “stepped” characteristic to the surface after the collapse, with the center of the caldera being the lowest and discontinuous step-like features increasing the elevation and gradually ending the caldera. Sulfur Banks is on a terrace on one of these steps. We talked earlier about how steam vents emit primarily water vapor and some other gasses such as sulfur dioxide. With Sulfur Banks, the water extends all the way down to the magma chamber, vaporizes, and, having a much high sulfur content, creates crystals on its way back up to the atmosphere
Above, I mentioned Pele. Pele is the legendary Brazilia… oh wait. Wrong Pele.
|I could not find a certified public domain image of Pele, so this will have to do.|
Pele is the Hawaiian goddess of volcanoes, fire, lightning, and wind. Pele is known for her creativity and passion, but most notably, she is known for her deep sense of love. Legend has it that every volcanic eruption in Hawaii is Pele’s way of longing to be with Lohiau, a young Hawaiian chief. However, Pele’s not just some whipped deity… she has been known to kill her husbands. Her home is the Halema’uma’u crater inside the Kilauea summit caldera. Pele is believed to control everything about a volcano, including when and where it erupts, and is one of the most important goddesses in Hawaiian religion. I knew about Pele before I knew about Jesus.
Similar to Pele is Nene, an extraordinarily dumb bird that is nevertheless the state bird of Hawaii. Sike.
This bird… wow. Most birds run from cars and trucks. This one waddles towards them. We had to slow way down and try to convince the bird to get off the street while we were driving past it. I think we must have put up a pretty convincing argument, because we got him to get off the road.
In conclusion, however, this was an absolutely incredible day, and I’m so glad that I can share it with you in my blog.