Gallery: Visiting a Lava Flow on Hawaii's Kilauea
01crack-in-a-lava-flow
Active Lava Flows ================= Visiting Hawaiii for the first time was a lot of fun -- so many sights that I've only known through textbooks were right there, laid out in front of me. As I mentioned to a passing tourist who asked what we were doing, visiting the Hawaiian volcanoes is the volcanologist's equivalent to visiting Graceland. Far and away the highlight of the trip was the chance to actually get up close and personal with an active lava flow itself. [Dr. Mike Poland](https://profile.usgs.gov/mpoland/) (HVO - USGS) lead a group that included me, 18 [Denison students](http://www.denison.edu/academics/departments/geosciences/), 3 other Denison Geosciences faculty and [Dr. Clive Oppenheimer](http://www.geog.cam.ac.uk/people/oppenheimer/) out to the active flow field on the East Rift Zone below Pu'u O'o (along with the current active ocean entry) on [Kilauea](http://volcanoes.usgs.gov/kilaueastatus.php). Now, getting out to the lava flows isn't easy during the day as you have to just head out over the 2009-today lava flow field in the direction that you think that latest breakouts might be. The clue is the "shimmering" air over the active breakouts, so off we went to find active, flowing lava. It took awhile to find it, but once we got there, it was spectacular ... and it as started off with heat and eerie glowing in the cracks beneath your feet. *Image: Erik Klemetti, March 12, 2013.*
02first-view-of-the-lava
The Lava Flow is Sighted ======================== This was my first sight of an active lava flow (ever! ... at least at this proximity). You can see the metallic-grey glassy carapace of the flow and those red-orange hot zones where molten basaltic lava (probably around 1000-1200°C) is visible. The flow surface mostly looks puffy and that's because many of the pahoehoe flows thicken by inflation (more on that later). *Image: Erik Klemetti, March 12, 2013.*
03pahoehoe-toe
Moving Lava =========== One of the first things you notice when you get up to a lava flow like this, beyond the heat, is the constant sound of cracking and popping. This is coming from the hardening skin of the lava flow breaking apart as the flow moves and expands. You can even see some of the shards of broken skin on the flow to the upper left of the little pahoehoe toe breakout in the middle of the image. Scale is a little tricky in these shots, but that pahoehoe toe is roughly a foot / 30 cm across. *Image: Erik Klemetti, March 12, 2013.*
04pahoehoe-toe-2
Budding Toes ============ Many of the lava flows grow by budding toes of new lava -- a weakness grows on the surface and a bleb of lava breaks through forming a small bulbous protrusion and fills, inflates and moves forward. Watch the lava move, you get the impression that it can flow easily (for a molten rock), but [as we know](http://stag-komodo.wired.com/wiredscience/2011/12/the-right-and-wrong-way-to-die-when-you-fall-into-lava/), it is actually quite a sticky substance. The comparison to watching honey flow seems to be quite an apt one when watching how these pahoehoe flows move (I'll post some video later). *Image: Erik Klemetti, March 12, 2013.*
05pahoehoe-toe-3
Pahoehoe Toes ============= Pahoehoe toes seem to be able to form almost anywhere along the advancing flow, filling in crevasses in the cracked (older) flow surface on which the lava is moving. Even in this fairly small toe (~30 cm across), you can begin to see the distinctive "ropey" texture that builds on pahoehoe flow surfaces. This texture can form before the flow surface even cools to the point where it appears that dark to the naked eye, suggesting that the lava can begin to bind quickly as it is exposed to the chilly (for lava) surface temperatures. *Image: Erik Klemetti, March 12, 2013.*
06overlapping-pahoehoe-toes
How Lava Flows Can Grow ======================= If you have enough pahoehoe toes, you can get the toes to start overlapping, creating a thickening lava flow front. Here, we have have a number of new toes (some still reddish from their internal heat) that have broken out all near each other. Eventually they begin to intertwine and run over each other -- if you were to cut through this lava flow after it cools completely, you'd see all the individual toes stacked up. *Image: Erik Klemetti, March 12, 2013.*
07sheets-of-lava
Sheet Breakouts =============== Now, not all breakouts lead to toes. This breakout (about a meter from end to end) is more of a sheet flow of pahoehoe lava rather than a toe. These sheets seemed to initially move much faster than the toes when the breakout starts, but seem to also cool faster, forming a ropey surface. You can see how thick the surface of the flow was where this sheet flow broke out and this hard shell likely didn't take too long to form (and then break due to continued lava input from upstream). *Image: Erik Klemetti, March 12, 2013.*
08small-breakout-from-sheet
Ropey Texture ============= Here is a close up of a small "sheet-like" breakout that occurred between some of the ropey segments of a solidifying part of the flow. This was very sluggish lava, oozing out more like taffy than honey. This might betray that this area of the flow wasn't getting a lot of new input behind it. *Image: Erik Klemetti, March 12, 2013.*
09rope-texture-of-pahoehoe
Flexible Lava Flow Skins ======================== The same could be said for this breakout (maybe 40-50 cm across) where the lava was obviously cooler as it broke out to form the black skin that piled up into pahoehoe ropes. It is remarkable how flexible the skin of the lava remains even after it has cooled to black, allowing for all those ropes to bend and distort as more lava skin piles up. *Image: Erik Klemetti, March 12, 2013.*
10two-breakouts-lead-to-lava-falls
Lava Falls ========== Some of the largest breakouts were quite impressive -- this one was roughly 2 meters across and produced a couple small "lava falls" that moved as a sheet. Then, when the lava collected at the bottom of the falls, the lava would begin to inflate and bud with toes like other areas of the breakout. The inflated portion of the flow in the middle of the image grew to be 15 cm thick (or more) rather quickly -- in a matter of minutes. *Image: Erik Klemetti, March 12, 2013.*
11breakouts-grow-quickly
Lava Flow Inflation =================== And it continued to inflate! This image was taken of the same breakout only 5 minutes to so later. You can see how much the lower portion of the flow inflated as the toes continued to grow and coalesce. The sheet-like lava falls are still visible, but the lava has had to find new places to drain as the inflating lower portion of the flow continued to grow (Dr. David Greene to the right for scale). *Image: Erik Klemetti, March 12, 2013.*
12sampling-lava
Sampling Lava ============= Now, what trip to a lava flow is complete without sampling the lava? Here I am sticking a rock hammer into the active lava. Two things struck me as I made my sampling dash. First, it is incredibly hot near even a small lava flow like this. Second, it was hard to get lava to actually stick to the hammer after digging into the relatively viscous lava flow. You can see that even with the honey comparison doesn't stand up when you sample lava, the behavior of the lava where it can be sampled is approaching taffy-like, where it breaks and stretches as a plastic. The heat of the lava after sampling is quite impressive -- it takes a long time for the sample to get cool enough to touch, even when it seems entirely solid. Same goes for the rock hammer. All that being said, being able to manipulate an active lava flow is definitely a highlight of my volcanic career, one of many that I accomplished on this trip to Hawai'i. *Image: Erik Klemetti, March 12, 2013.*
