Volcanic eruptions and fumes, oh my!

5 09 2008

The night after I helped set up the time-lapse camera to record any collapses of the vent rim, there were two magmatic explosive events. The rim area beneath and to the east of the plume is littered with spatter material. The explosions happened about an hour after I visited the visitor overlook. If only I’d been an hour later! At any rate, I was able to go down into the caldera again yesterday to assist with sampling gases from fumaroles. These are holes in the ground near volcanoes that emit gases and steam. We decided to see the spatter material before venturing in on foot.

Let’s just say it’s a good thing that this road is closed to the public. Some of the ejected material was incandescent at the time of eruption, which signifies fairly high temperatures.

We left that area and journeyed to the less-travelled southern end of Halema`uma`u crater. Here’s a view of the crater wall that you can’t see from the Observatory or Jaggar Museum.

We continued hiking around to the western edge of the crater and stopped for a bit to watch the plume. The vent was making banging noises like it had all day on Tuesday, and after a while it switched to gas rushing sounds. It’s akin to the noise a 747 jet makes as it lands. At one point the plume almost died out, and then it resumed more vigorous puffing and turned brown.

Our resident gas geochemist was nice enough to model for me.

He’s standing in an area of the crater known as the Postal Rift. When Halema`uma`u was filled entirely with lava back in 1919, visitors could walk right up to the rift and dip their postcards into the lava. The edges would become a nicely singed, unique souvenir of their visit to Kilauea. Try to imagine that whole crater and the rift where the scientist is standing as a lava lake. Pretty amazing.

So, I’m sure you’re all curious about what sulfur dioxide does to the areas surrounding it.

It makes sulfur crystals! When sulfur-rich gas seeps out of the earth and the area remains relatively undisturbed, it gives sulfur crystals the chance to grow. They’re beautiful.

Here’s a fumarole up close and personal. The crystals are about 1/2-3/4 inch at their longest. They also smell like rotten eggs. Hey, perfection is hard!

This is what we do with fumaroles…we sample the gas they emit! I’m using a technique called evacuated-bottle fumarole gas sampling. First we measure the temperature of the fumarole using a probe. The temperature around the crater is right near the boiling temperature at this altitude = 94.8 degrees Celsius. After that we insert a teflon tube into the fumarole, and connect the tube to a specially-made vacuum-sealed Pyrex bottle. We then pump the gas into the bottle slowly, and make sure that it cools and condenses enough to close the bottle off.

Once we get back to the lab we run the samples through a manometer (pressure-reading device) to compare the gas pressure in the bottles to the ambient room pressure. After that we stick it on a gas chromatograph and measure the bottle’s levels of air, water, CO2, and SO2. Fumaroles from different areas have different gas concentrations, and this helps us to understand the magma and gas beneath the crater’s surface.

Not a day goes by without me learning something incredibly interesting!

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On the level.

6 08 2008

My last 3 days of work have been out in the field. We’re in the midst of a levelling campaign here at the Hawaiian Volcano Observatory. It is by far the most expensive data collection that is undertaken here in terms of sheer man-hours, and it’s not easy to execute. We’ve gone out in crews of 4 or 5 for the last week to take measurements on different “level lines,” (pre-measured routes) around Kilauea. After the data has been collected it is compared to last year’s data to detect any changes in the surface of the volcano. It’s known as dry-tilt, or single-setup levelling. SSL is the more correct name for what we’ve been doing.

The most exciting part of the whole process for me has been the location. I finally had the opportunity to go into the sections of Kilauea’s caldera that have been closed to the public since the March explosion events. Here’s the plume from nearly underneath of it.

Who thought that poisonous gas could look so beautiful? Due to the lethally high concentrations of sulfur dioxide in the plume’s immediate vicinity, we have to wear something special to do any field work nearby.

Now THAT is a fashion statement. I tried in vain to stop myself from saying, “Luke, I am your father!” repeatedly. The gas masks filter enough noxious fumes to allow us to work in SO2 concentrations up to 10 times the levels considered safe for breathing. The parking area behind me has been closed since the March explosions. It is coated with a fine layer of explosive materials now. That’s the HVO Deformation Group truck in the background.

Here is my levelling crew from today. We were right next to Halema`uma`u’s open vent, which is the origin of the plume. It was incredible.

Here’s one more shot of the amazing gas mask getup for good measure. We have to wear the helmets in case another explosive event occurs. The first notable one since April happened last Friday, so the safety precautions are certainly necessary.

Ashley and I aren’t phased by the volcano behind us, however. We’re still sending that Aloha spirit your way!