From lava to the stars.

9 09 2008

We made a pretty stunning discovery in Halema`uma`u on Friday. Many months after the explosion that first opened the vent, we finally had visual confirmation of a roiling, active lava lake inside. Some of the scientists were over the vent in a helicopter, and they were able to get pictures and video of the lava. The best estimate is that it’s about 100 meters below the top of the vent. A few hours after the helicopter overflight, I went out with the gas geochemistry team to do Fourier transform infrared spectroscopy, or FTIR since the lava was visible.

The round part on top of the tripod is a telescope, and the box on top is the spectrometer. Anyway, since we were on the rim and right over the vent, I think perhaps a picture of the lava’s incandescence is in order.

Yep, that’s lava down there. That sort of glow just doesn’t normally happen during daylight hours. It was truly impressive to stand right above a lava lake. The noises were loud, tremendous, and unrelenting. If it wasn’t clanging with rock falls, it was making gas-rushing noises that sounded like jet engines. The earth is alive!

I have a special treat for all of you. My colleague Brian White was down on the other side of the vent from where I was, and he recorded video. You can finally hear the noises I keep writing about! Make sure your sound is turned on. It’s possible to see some of the incandescence as well.

Thanks Brian!

Saturday brought more impressive sights. I ventured up Mauna Kea with some colleagues to check out the view and do some stargazing. The name Mauna Kea means White Mountain, and that’s because it frequently has snow on its peak during winter. It stands 13,796 feet above the ocean, and is older than Mauna Loa and Kilauea. Mauna Kea is considered dormant, but not extinct. It’s also home to some of the world’s best telescopes and astronomical observatories.

Those are the Keck Twins, formally known as the W.M. Keck Observatory. They sit 85 meters apart at Mauna Kea’s summit and they each have a 10 meter primary mirror.

Those are cinder cones on the north flank of Mauna Kea. Since the volcano is in its “post-shield building” stage, it is literally pockmarked with cones like these.

This is the NASA Infrared Telescope Facility. It was posing nicely for me. It was built to support the Voyager missions.

This is the Caltech Submillimeter Observatory with its dome open.

I don’t think that one needs much explanation.

Here we have the moon, some stars, and the Subaru Telescope.

Last but certainly not least, I give you this:

Yes, that’s a laser issuing from one of the Keck Twins. It actually creates an artificial star that astronomers use to establish a relative location in the sky. I’m sure it does some other neat things, too, but I’m not aware of what they are, exactly. ***EDIT*** Check out Andrew Cooper’s comment at the end of this post for the actual use of the artificial star. He knows what he’s talking about!

If you’re ever in Hawai`i, sunset on Mauna Kea is definitely in order. Oh yeah…you might want to check out any available lava lakes, too.

Advertisements




It’s work time…field work, that is.

26 08 2008

It’s high time that I posted about the field work I’ve been doing lately. Before I became sick last week, I was out mapping the newest lava flows at Waikupanaha. Well, it was a gorgeous day and I did manage to snap a few pictures before the hospital called.

While hiking to where we were to begin our mapping, we heard and saw some lava bubble bursts to the left of the ocean entry plume. Unfortunately, a watched pot never boils and neither does a watched ocean entry. As soon as I pulled my camera out, the bursts stopped. Ah well, at least the ocean entry plume still looked good.

This is a view to the south, and you can see the pali (or cliff) at the right of the frame. The lava flows toward the ocean from very far up the pali, sometimes aboveground and mostly underground through lava tubes.

The way we map new lava breakouts is by putting handheld GPS units on Tracking mode and then walking along the boundaries of the fresh lava. It’s a good way to map, since you can set the GPS to record your position at intervals of three seconds. The level of accuracy is enough for our purposes. After all, the flow field changes fairly often.

Moving on to the field work I did on Friday (it wasn’t too strenuous, don’t worry)! We met up with a cultural resources guy from Pohakuloa Training Area, a massive area between Mauna Loa and Mauna Kea where the Army and Marines practice bombing and combat. The samples we needed to obtain were on the military’s land, so we have to go through the proper channels to collect them.

There’s a bit of archaeology in what we were doing there.

That is a pit dug by the ancient Hawaiians. No one is sure why they dug these pits, which happen to be about 9,000 feet up the slope of Mauna Loa. We collected samples of the displaced rocks to perform the same Chlorine-36 cosmogenic isotope dating that we did on Mauna Loa’s summit. The reddish lava flow that the pits are situated in is of unknown age, so we’re also going to date that as well. It should give us an idea of how long ago the Hawaiians made the pits.

I suppose it can’t hurt to throw in a picture of the other massive volcano on this island. If you can make out a small whitish blob in the left foreground, past the plants…that’s our truck. This might give some sense of how gentle this particular slope of Mauna Loa is. Trust me, they’re not all like that!

Tonight is my last night housesitting, so my internet access (and consequently posting) should pick up a bit this week.





Highly educational

28 07 2008

After last week’s intense office work, I was dying to get back in the field. Since my knee wasn’t cleared until Saturday, my field experiences would have to be tame. Still, that doesn’t mean they were boring! Since there are a good number of pictures, I’m going to break things up into Thursday and Friday. Tonight’s post will cover last Thursday.

My boss organized a field trip for anyone interested to Kona’s Gold Coast. 13 of us set out from HVO early Thursday to begin a day of learning in the best way possible – while standing in front of the subjects of our study! The first stop was Rainbow Falls outside of Hilo.

While the average tourist might have stopped here to marvel at the falls themselves (and the tiny rainbow you can just glimpse at their base), we were here to look at the volcanic stratigraphy. Behind the mist of the falls it’s possible to glimpse columnar basalt. Lava flows of several different ages are visible here.

The next stop was at Kaumana Cave, a well-known skylight in a massive lava tube created by the 1881 eruption of Mauna Loa. The tube is about 25 miles long, and definitely illustrates the hazards posed by lava flows. The guy at the bottom of the picture is a visiting scientist from Japan, and the guy on top of the tube is one of our preeminent seismologists.

While stopped at a kipuka for some geologic question and answer time, I spotted this plant that was reveling in the morning dew. Just thought you might like some Hawaiian foliage to brighten your day! If any of you biologically-inclined sorts know what kind of plant this is, do tell.

This is an incredibly interesting thing to geologists. It’s called a xenolith, which translates from Latin as “foreign rock.” That’s exactly what it is. This particular xenolith is dunite, a rock that is composed of coarse grains of olivine and originates in the earth’s crust. Essentially, the basalt grabbed the piece of dunite from where it formed deep below the surface and carried it upward, where it came to rest inside the flow. This particular lava flow is one of the best sources of xenoliths in the entire world. It is from Hualalai volcano, and the eruption took place in 1800. There were plenty of other xenoliths nearby ranging from clinopyroxene to gabbro and more. This is amazingly interesting for someone who is captivated by crust-eruption interactions (yeah, that would be me).

Our trip informed us in detail about Kilauea, Mauna Loa, Mauna Kea, and Hualalai. The only volcano we didn’t touch on was Kohala, the oldest one on the island. My boss is so knowledgeable on all things Hawai`i that it blows my mind. I know he was born and raised on the islands, and that he’s been working at HVO for over 20 years…but still! He’s brilliant. Here is where I ought to mention that he’s the scientist who proved that Kilauea volcano has a deep plumbing system. This is critical to our understanding of the volcano’s eruptions. This is such an amazing opportunity.

After our long day of learning, we headed down to Mauna Loa’s 1881 lava flow on the western portion of the island. The flow took 8 days to reach the coast, and reach the coast it did. It travelled over 31 miles, and this is how it looks today.

Not too shabby, is it? The grass is a pretty nasty invasive species and is resistant to fire. Eradicating it is nearly impossible, but at least it makes the pictures look good. We ended the educational portion of our trip at Anaehoomalu Bay (known as A Bay by people who don’t want to attempt THAT tongue-twister). You can just look at the water and guess what we did when we got there. I’m not going to give away all of our secrets.

Tomorrow will be pictures and talk about Friday’s gravity survey. This Thursday I’m going to the southern end of the island to collect samples from littoral cone deposits on Mauna Loa’s Southwest Rift Zone. I’m ready and waiting for the fieldwork to begin anew!