Thursday, July 30, 2015

For the love of lava: Adventures on Tolbachik volcano

-Janine

Last month I had the amazing opportunity to do field work on Tolbachik volcano in Kamchatka, Russia. I spent a week on one of the lava flows produced during the 2012-2013 eruption and was blown away by the formations and textures that the flowing rock can create. Here are some of the features that caught my eye while I was coming to the realization of just how awesome basalt can be. I'm sure you can imagine the molten rock flowing and fracturing, then oozing out when the opportunity presents itself.

NASA Advanced Land Imager (ALI, on the Earth Observing-1 satellite) false color image showing the hot lava flow on December 1st, 2012. Image courtesy of the NASA Earth Observatory.
View of the main Tolbachik complex from camp, right next to the lava flow.




This tongue of lava formed a solid shell then the still-fluid lava inside cracked it open so it could keep moving forward.
Not too far under the crust is a bright oxidation discoloration - this tells us that it was hot! But we already knew that. This lava is crunchy to walk on and looks a lot like tree bark on the surface.
This area of lava produced folds as the surface was a little more solid than the flowing lava underneath. After this had formed the lava inflated and deflated (probably multiple times) breaking up the lava into this very sharp, very difficult to walk over lava hazard. Tolbachik is in the background.
This one reminded me of the New Zealand Koru design. There is a bit of home everywhere.
Here the solid lava surface cracked open and more fluid lava tried to squeeze upward through the fracture. Foot at the bottom for scale.
I like how this image inspires thoughts of Nightmare on Elm Street.
These are lavacicles (not a technical term) that formed by dripping lava in the top of a lava tube once the lava flowed through and emptied.
The gasses in the lava met up and joined these vesicles (holes left by the bubbles), then they were stretched as the lava was flowing. You can see different areas of folding through the lava.
This discoloration caught my attention! It was like an oil slick on the surface of the flow (clearly was not an oil slick).
This little hole (~15 cm across) is actually a doorway into a very hot (>500 degrees C) lava tube. We were drawn to it by the obvious hot air and roaring sound coming from it. Upon throwing rocks in (from a safe distance!) we didn't hear them hit the ground.
This is a classic 'ropy' texture of pahoehoe lava.
This stuff is SHARP! When lava cools quickly it is very glassy, hence the gloves.
The lava surface can have a large amount of detail and different colors.
Skylight - a hole that formed over a lava tube.
Steam is still flowing through cracks from the hot lava beneath.
Panorama of the lava flow (there is another one from the same eruption behind me) taken from one of Tolbachik's many scoria cones. You can see the different smooth (pahoehoe) and rough (a'a') lava. Tolbachik is in the upper left with the extinct Udina volcano to the right.

I have always been more of an explosive volcanologist - excited more by pyroclastic density currents and explosive eruptions. Tolbachik has opened my eyes to how fascinating and complex basaltic lava is. If you get a chance to check out a lava flow, take very sturdy and tough boots, tough gloves, and long pants to keep yourself safe. Always be very careful, as you can see there are a lot of hollow places under the glassy crust and it can have fracture networks waiting to break. Although there are hazards with every aspect of volcanoes, as we can see here, there is also great beauty. I hope these images have ignited your imagination and inspired a love for lava.






No comments:

Post a Comment