Monday, January 23, 2012

High-Speed Video of an Explosion

Sample 500 fps high-speed video of a Santiaguito explosion downsampled to 10 fps. Natural duration is 4.6 s.

credit: Piergiorgio Scarlato, Corrado Cimarelli, Daniele Andronico, and Elisabetta Del Bello

Saturday, January 21, 2012

Block and Ash Flow from the Southeast Lava Flow Station

Time-lapse animation and seismo-acoustic traces from the southeast lava flow of Santiaguito volcano, Guatemala. The active dome is in the background. Many of the events generate clear rock fall seismic and infrasound signals. Look closely to see the lava flowing in the foreground. The animation depicts a two-hour period sampled every five seconds on the morning of January 5, 2012. Time synchronized waveforms were recorded at the lava flow station.

credit: Jeff Johnson

Wednesday, January 18, 2012

Preliminary Results: Time-Lapse Photography and Seismo-Acoustic Tilt

Time-lapse photography with particle image velocimetry and seismo-acoustic tilt signals for the night of January 7. Note clearly visible inflation and deflation of the dome, the active lava flow to the south (left side of animation), and visible explosions around 21:50, 22:15, and 24:31.

Animation of nighttime photographs of the dome taken from Santa Maria with full-image PIV.
credit: Ben Andrews and Jeff Johnson

Seismo-acoustic tilt signals for the period covered by the above animation.
credit: Jeff Johnson

Interview with Jeff Johnson and Kyle Brill

Vulcanólogos extranjeros estudian el Santiaguito

Monday, January 16, 2012

Updates will continue

Mountain guide Armando Pineda, with John Lyons and Ben Andrews in reflection

We will continue to add links to photo albums, videos, and data from the expedition as they become available. Please continue to check back for updates.

Sunday, January 15, 2012

Thermal Video of an Explosion

Sample uncalibrated thermal IR video of a January 8, 2012, Santiaguito explosion.

credit: Piergiorgio Scarlato, Corrado Cimarelli, Daniele Andronico, and Elisabetta Del Bello

Tuesday, January 10, 2012

Santiaguito Volcano From Top to Bottom (Jan. 4 to 8)

Introduction and photography
by Benjamin Phillips

Three teams conducted final stages of this month's expedition at Santiaguito over the past few days. The high-speed video team (P.G. Scarlato, Corrado Cimarelli, Daniele Andronico, Elisabetta Del Bello) and photogrammetry team (Ben Andrews, Kirsten Chojnicki, Ben Phillips, Andrew Nies) looked down on the active dome from a perch atop 12,375 ft Santa Maria volcano. A mile below in the dome moat the seismoacoustic team (John Lyons, Cara Shonsey, Kyle Brill, Josh Richardson, Jake Anderson, and Armando Pineda) worked to retrieve data and equipment, and make permanent one of the installations. Following are accounts of these efforts from members of each team.

by John Lyons

For the return to the domes and the extraction of the two seismic, tilt and infrasound stations we assembled the A-Team, including two new members from Michigan Tech (Kyle Brill and Josh Richardson).  Jeff had fallen ill, so he stayed behind to orchestrate the final days of the experiment from Xela.  Cara, Jake, Josh, Kyle, Armando and myself headed into the domes early Friday afternoon.  Josh, eager to get his legs under him and get into the domes for the first time, valiantly offered to carry the extra car battery down (and then up)  to reinforce the long-term seismic and tilt station.  And down, down, down toward the domes we went. There was more ash on the trail this time, and although the water-polished andesite of the canaletta was slick with the ash patina, all major falls were avoided.

We reached the base of the domes and searched out the stash of water and food that we had left.  Thinking about the climb up the rock fall to the site of our installation, we decided to filter most of our water from a large pool in the smooth lava flows near the camp instead of hauling the extra weight.  This would prove a somewhat bitter decision.

Arriving near the installation, which we've dubbed El Playon (the big beach), we set up camp just before dark and watched an incredible moon rise over the summit of Sta. Maria.  With camp set, we headed out to check on the status of each of the seismic - tilt - infrasound stations, keeping a close eye on the incandescent glow from the top of Caliente.  Two stations were running well, but the third had suffered a slow death by drowning due to very heavy rains the night before and a leaky dry bag.  We quickly pulled the soggy, mud-caked digitizer, cables and battery out of the bag and disconnected the power.  Fortunately, we had the back-up battery, which we connected while holding our breath and crossing our fingers, hoping that the flood hand´t damaged other parts of the stations. Wiping the mud from the screen, we could see…. it was alive!  Whew, disaster avoided, and the late-night visit to the stations had saved 8 hours of potentially lost data.

Meanwhile, the volcano was much more active than during our first trip to the domes, with small gas explosions popping off at about twice per hour. We ambled back to camp in the moonlight and called up to the summit team by radio. After chatting with the Bens, we flashed our headlamps up toward the summit and got a response, more than a mile away. We all turned our headlamps upward and had a little dance party while Ben shot some photos.  We look like ants with headlamps.

Early the next morning we revisited each seismic station and connected solar panels to all the batteries.  I popped up to Jeff´s time lapse camera to swap it out with another, programed to record during the long-term deployment. We backed-up all the data, packed camp and got ready to climb up the dome located just the the west of Caliente, La Mitad, where we planned to spend our last night.  Although this put us even closer to the booming summit of Caliente, we were cautiously optimistic that the explosions were not currently throwing bombs onto La Mitad, and the different perspective, nearly level with the glowing summit was worth the climb.  Unfortunately, we were short on water and the clear, cool pool that we had planned to filter from had been half filled with sediment and was now a milky blue following the heavy rain.  It tasted terrible, like salty sulfur, and effervesced mildly after having been bottled for a while.  There was a good deal of speculation about what exactly we were drinking, but no one wanted to make the hike down and back up the rock fall to get fresh water, so we suffered the strange Santiaguito brew knowing that we had fresh, delicious water waiting for us after our descent.

After a steep scramble up the side of La Mitad, we creeped around the tall spines of lava and found a few well protected camp sites.  The clouds had rolled in and a light rain was falling, so we retired to our tents for most of the afternoon, waiting for a view.  The clouds persisted until after dinner, and everyone except Armando and me turned in for the night, knowing we had a big day of working and hiking ahead of us.  While we were setting up another time lapse camera, the clouds cleared and we were awarded with two beautiful explosion that showered Caliente with incandescent bombs.  Several large explosions occurred during the night and the coarse ash would fall on the tent several minutes later, sounding like short rain showers.

Up early to pack camp and get to work.  Down the slippery slope of La Mitad to stop acquisition on two of the stations and to transfer the batteries and extra memory to the long-term station.  The A-Team worked in overdrive and a couple hours later we were ready to descend the rock fall with loaded packs, beyond eager to get at that fresh water.  After drinking down half of our ague dulce, we shouldered our packs and cracked a few jokes before the last, long climb out of the domes. It was several hours of torture, and we could have swore that the dense vegetation was trying to keep us from leaving, but we arrived tired, thirsty and dirty just before dark in Llanos de Pinal, content knowing that we had the data, the equipment and ourselves back in one piece.

Camp at the domes as viewed from Santa Maria (three spots of light at lower right)

by Corrado Cimarelli

Hi guys, here we go with the second post after the trip to the lava flow. 
How do people say ... when you step back things look much clearer, especially if you have good tele objectives! 

We knew we should have had a better view of Caliente dome from the top of Santa Maria and this is exactly what happened. But, nothing comes easy with Santiaguito and as usual the volcano doesn't reveal himself if you don't give something back. This time we had to climb all the way up to Santa Maria summit (3700 m asl) from the very bottom (2500 m) with all the scientific equipment, plus camping gear and a lot of water. We surely wouldn't have make it without the help of the wonderful Lopez Family. They are hard working farmers, they say they are "gente de mais" but for the occasion they helped us carrying the extra load. Jeronimo is a rock and Ector (Jeronimo's son) could easily compete for a triathlon (this is actually what he wants to do next year, we are sure he will get a very good ranking!). On top of that we needed to ask for security assistance from the local police (PNC) since Santa Maria is very popular among the locals and you never know who you are going to meet in the forest. We made it to the top after about 4 hours of climbing.

The first day at the summit was frustrating, the dome seemed sleepy and just started some interesting activity when it was completely clouded. The time window when you can observe the dome is quite narrow given the rhythm of the eruptions (one every hour on average) so early morning and late afternoon are usually the best timing - of course they are also the colder hours on the windy top of Santa Maria! Trying to operate the camera with frozen hands is not trivial and the batteries can freak out pretty easily with moisture and cold. Radio-sync controls of orthophotogrammetry cameras didn't work as expected but excellent team work of Ben A., Kirsten, Ben P., and Andrew with walkie talkie did make things work. Some minor trouble with cable connections from our part just for the thrill, but we got it sorted out pretty quickly. Finally just as a welcome we had -6 C the first night of camping! 

Having paid the toll on the first day, over the following days Caliente blessed us with a gorgeous series of day and night explosions revealing all his magnificence. All the teams at the top got tons of gigas recorded. High speed and thermal videos reveal set of fractures opening in series at the margin of the dome and jets of gas and ash streaming through and soon converting into convective eddies and forming the plume... for the joy of Kirsten. Ejected ballistics are only observed toward the side of the active lava flows and frequent block and ash flows stream down along the same flanks. Sometimes blocks as big as a bus roll down, break and disappear in the steep valley at the foot of the dome, leaving behind just the trace of suspended ash.
Running out of water and batteries we headed back to Quetzaltenango with all our stuff and eager for a shower and a proper dinner!

While I am writing we are travelling back from Quetzaltenango to La Antigua - some of us will take a rest in this lively city before going back home, and others will soon move to Volcan de Fuego to install seismic arrays. The high speed and thermal cameras team will follow this group in a couple of days and repeat the camping experience on Fuego hoping to bring back some more gigas...

Hasta pronto

by Ben Anderson

Hi everyone,
I am back in DC and trying to process data from the (very successful!) trip to Santiaguito.  The expedition was a great deal of fun, I met many new people and am excited to work with them on this and future projects.  Most importantly I want to thank Jeff Johnson for helping to put together a great trip, and my photo team for making the data collection possible: Ben P, Kirsten, and Andrew – without those three, there would be no photogrammetry data.

I arrived in Xela several days after everyone else, and thus the hike to the summit on January 4 constituted my introduction to Santa Maria and Santiaguito.  It is a Big mountain.  Upon reaching the camp I was greeted by clouds. . . that cleared right after sunset to show a great view of the incandescent dome.  That first night I tested one of the cameras and radios to take several time lapse series of photos of the eruption.  The photos that resulted are pretty cool and helped us figure out what exposure settings we’d use in subsequent nights.

The original plan for January 5th was to deploy the cameras about 500 m apart in an arc along the edge of the 1902 scarp.  Reality, however, intruded on this plan.  First, the camera radios didn’t want to talk to each other – which was funny as they had worked together the night before at Hotel Modelo.  At this point we realized that there were different versions of the firmware installed on the radios, thus they wouldn’t play nice and we couldn’t get them to communicate over distances much greater than 5 m.  At this point we also realized that although it is pretty easy to draw points on a map separated by more than 300 vertical meters, it is altogether different to have to repeatedly make such a journey over the uneven terrain of Santa Maria. . .  So we ended up deploying the cameras a few hundred meters away from one another, with a total elevation spread of ~150 m.  We then used talkie-walkies to manually trigger the intervalometers on the 5 cameras.  Over the next few days we encountered a few more problems: fog, clouds, short battery life, more clouds, finicky SD cards, a cloud, and LCD screens that wouldn’t turn off.  Fortunately, those problems turned out to be pretty minor.  With that we were off and running. 
We collected >10 hours of synchronized images from the 5 cameras.  Some of the images have been stitched into a movie shown elsewhere on the blog.  We are still making sense of the image sequences, but here are some rough observations:

1) Parts of the dome are moving at >3.5 m/h.
2) Local inflation/deflation of the dome can occur as fast as 2.5 m in 13 minutes.
3) There are very hot regions of the dome that show no motion and persist over the duration of observations.
I am currently working on transforming the images into 3d surface models using photogrammetry techniques.  Stay tuned for new developments. 

Wednesday, January 4, 2012

Southeast Lava Flow Trip (Jan. 3)

by Corrado Cimarelli
photography by Benjamin Phillips

This is dedicated to all my friends who are convinced I am on Christmas holidays in South America. Yesterday was supposed to be a relaxed day. Juan and Angel drove us to La Finca Faro, where the coffee and macadamia plantations are threatened by the two lava flows starting from the summit of Santiaguito. We descended in altitude about 2000 meters from the colder Quetzaltenango down to the Observatory at the base of Santiaguito. During the short visit to the Observatory we got to know Julio who is keeping the observatory active and served as group guide for the day. We walked up again about 700 meters in altitude zig-zagging in the plantations, too curious to resist fresh coffee beans and macadamias on our way up. There is not much to chew from fresh coffee beens, but they are sweet and tasty in the mouth.

If it wasn't for the constant slope and the deeply carved lahar deposits you would probably forget you are walking toward the active dome - this is probably what the plantation workers think every day going harvesting. With the help of the little 4-wheel drive of Angel the whole group made it to the observation point at the levees of the lava flow and installed our high speed and thermal cameras. Cloudy skies constantly made PG, Daniele, Betta and me switch our observation from the summit of the dome to the rock falls of the slowly advancing lava front 100 meters distant, but we got our data anyway. Impressive explosions at the summit often cause ejected blocks rolling down to along the flanks of the dome for hundreds of meters. Rumbling of the lava flow slowly advancing is impressive too, we are going to see what our installed microphones have recorded....

Today we are going to the chilly summit of Santa Maria and this is supposed to be a very long day before we set our camp. We will get great videos from there so crossed fingers! By the way yesterday wasn't soooooo relaxed, ask my blisters...

Santiaguito Dome Trip (Dec. 31 to Jan. 2)

by Jeff Johnson
photography by Benjamin Phillips

On the last day of 2011 our group heads in to Santiaguito dome for two nights and three days of seismo-acoustic-tilt station installation.  Access to the domes is challenging and requires a descent of about 1000 m, first on a traverse through cloud forest, then through a tunnel of vegetation (those who are tall suffer the most), and finally down a steep ravine called the canaleta.  The canaleta is comprised of water-polished lava coated with a thin layer of ash and can be treacherous.  Upon reaching the bottom we are on the playon, a vast flat area between the Santa Maria (SM) caldera rim and the Santiaguito (SG) domes.  The playon is littered with poorly sorted lahar debris ranging from refrigerators to fine sand.

Our guide Armando leads us boulder-hopping down the playon to a hidden camp nestled in the woods near the caldera wall.  It is a excellent site with views of Brujo Dome across the playon.  It is also shielded from winds and also has flowing water.  Tents go up and we plan our next moves.  Because field work at the Santiaguito domes is tough and just getting to the campsite is an accomplishment a subset of our group is ready to call it a day.  A few others are just too excited to be back here in this volcanic Disneyland so four of us head out to carry loads and conduct reconnaissance.

Each of us loads packs with batteries (53 Amp-hours each) and we head toward the deployment site.  Our route wends along the "moat" separating the SM edifice and SG domes (imagine the domes as the castle).  Just beyond the entrance to the canaleta the moat steepens as it goes over a constricted passage.  Car-sized boulders choke the gulley and we climb 300 m in a series of rubbly steps.  I like to refer to the passage as the Khumbu rock fall in honor of its similarities to the ice fall at Mount Everest.  Above the Khumbu rock fall the gap between SG and SM broadens and becomes flat.  Some 15 years ago there was a lake here, but it is presently filled with sediments following debris avalanches from SM.  By now it is dusk and as we turn the corner around the Mitad dome we finally see the glow from Caliente dome (the currently active dome of SG).  Caliente towers 400 m above us and is about 800 m distant.  Here we stash our batteries and sit down to await an explosion.  

The dome glow is strong suggesting an active, and perhaps enhanced, effusion of lava.  Occasionally a degassing burst will send a vapor column hundreds of meters above the summit.  The plume is lit both by incandescence and the moon.  Frequent rock fall can be seen, but not heard, originating from both SG and SM, which towers 1500 m above us.  Although we don't observe our anticipated explosion prior to heading down it is still a downright awe-inspiring place to spend a New Year's Eve.  We finally decide to downclimb the Khumbu rock fall using our headlamps and arrive at camp at 10:00 PM.  Everyone there is asleep.

On day two of the dome excursion the Italian team (see Corada's report) head out to climb the domes while we head back up to Khumbu rock fall to deploy.  Our goal is to install three stations in a 150-m aperture tripartite configuration.  Two stations will be equidistant from the vent (about 500 m away) and will be comprised of triaxial broadband seismometers and biaxial tiltmeters.  A third station will record seismic and infrasound from a pair of microphones.  In order to deploy the seismic and tilt deep holes must be excavated to isolate seismo-tilt from meteorological influences.  

The deeper the hole the better.  John, Jake, and Andrew, who comprise the seismic team, are charged with digging the three holes.  John and Jake vie for deeper holes and are both only satisfied when they are a meter deep and large enough to bury a small horse.  We decide to coin station names (SJON, SJAK, and SAND) as a contraction of the volcano (Santiaguito) and the digger's name.

Deploying tilt is especially difficult because the sensor must be oriented and level and is very sensitive.  One component can be satisfactorily leveled, but then fall out of true as the second component is leveled.  At station SJAK the leveling of the tilt is particularly onerous.  We read off voltages as John, stuck in the hole gently tweaks the instrument and packs tephra around it.  At one point we are interrupted by an eruption.  We hear the boom before we see it.  Looking up we see bombs raining out of the column.  One bomb lands on the slopes and rolls in our direction coming to its resting place, which is not all that far away.

Finally, after dark, the tiltmeter is leveled.  We push the button to start acquisition and retreat to a safer vantage point to wait for another explosion.

Two hours later and still there is no bang.  Its getting cold and we decide that we will leave at 9:00 PM explosion or not.  At 8:56 we get what we waited for.  Incandescent projectiles are thrown onto the flanks of the upper dome and a plume shoots upward from the summit.  We navigate the Khumbu Rock Fall and return to camp by 10:30 PM.

On the third day we must head back to Xela.  One group heads out directly while another smaller group goes to check on the seismic sites before ascending the canaleta.  In order to verify that our stations are functioning properly we bring a laptop and a tent in which to view the data.  Some of the stations require some minor corrections, e.g., reduction of gain on one of the channels, so we are grateful to be able to make these corrections before leaving the stations for a week's worth of data acquisition.

The hike out from SG is, as always, brutal.  We retrace our steps up the slippery canaleta, through the ash-covered vegetation, and back to the waiting microbus, which bumps and convulses its way down to Xela.  Tonight we get to eat (Tecum) hamburgers and drink beer. Tomorrow we will go visit the lava flows on the other side of the volcano.

Monday, January 2, 2012

Happy New Year

by Benjamin Phillips

Back from the domes safe and sound. All are happy, and tired. More details to come...