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Climber's Bivouac, Mount St. Helens National Volcanic Monument
The movements of mountains are curious things. Dramatic earthquakes and sudden eruptions grab all the headlines, but the fact that these giant masses can be constantly moving–shifting, shaking, straining, and subsiding–may be an even more amazing phenomenon.
Of course, the importance of continual, subtle movements is not lost on the scientists who study volcanoes.
Which is why, with the mountain still steaming from its recent round of eruptions in early October, I'm accompanying a crew to the south side of Mount St. Helens. This team is setting up stations on the flanks and rim of the volcano to measure the volcano's movements–even movements so small as a millimeter.
The station they are installing today will use global positioning satellites to track its position on the mountain. It will be used to tell what parts of the mountain are moving, when, and by how much–data which might be linked to observations of magma movement, gas levels, and other measurements. It will join a network of other devices now arrayed like wireless electrodes around the body of the mountain: cameras, seismographs, gas samplers, and other tools used to monitor the volcano's every move.
The install team, which is part of an ambitious new earth science program called EarthScope, aims to get their equipment in before winter weather hits the mountain. Some of this weather already hit a few weeks ago, preventing the group from finishing work on the last of five stations they had aimed to install. The mountain has been socked in since, with rains, snow, and fog making it unsafe for the helicopter operations they require to do their work. As is always the case in the Northwest, they can't count on the weather providing too many more good days to accomplish their work.
Today, however, the morning dawns promisingly, casting a pinkish glow on the few clouds lingering at the volcano's rim.
I'm standing in a trailhead parking lot with Katrin Hafner, who leads this team; Peter Gray, their field engineer; and Angie Diefenbach, a recent college graduate whose first day as an employee was yesterday. They make up the Pacific Northwest office of the Plate Boundary Observatory (PBO), which is the geodetic component of EarthScope.
The parking lot where we've assembled is usually used as a staging area for climbers ascending to the rim of the crater, but it's deserted now except for us. Several weeks ago, when the mountain began acting up, a large area around the volcano's perimeter was closed to visitors without special permission to conduct scientific work or observation. Today, we use a key to open the gated service road to get here.
We're waiting for the helicopter, having set out the tools the team thought might be useful up on the mountain. We've also assembled a "swing set": a frame of metal cylinders that supports a solar panel, batteries, satellite, and radio equipment. This is the power and communications part of the station, which the team will link by cable to the GPS tower. Assembling the swing set is like raising a tent–complete with the puzzle of putting pieces together.
While we build the swing set and make preparations, Katrin keeps the team moving. "The less we have to do on the mountain, the better," she explains. Katrin once spent eight months as manager of the South Pole station in Antarctica, but that hasn't made her immune to the cold of this morning. She's moving around, trying to keep warm. Katrin, like Peter, is dressed in a yellow work bodysuit.
Preparing is obviously important for fieldwork on the mountain. "It's hard to remember to bring everything along," says Peter, a tall, thoughtful man, who's obviously skilled with tools. "Sometimes we have to improvise because of that."
Angie, who is upbeat and works hard at what she knows how to do so far, makes herself useful by moving a bucket of gear over to the landing area. She jokes that she is trying to bulk up so she can haul more than one of the heavy batteries at a time. She's told she'll spend lots of time in the field for this job–"the fun part of geology," as she puts it.
Eventually, the helicopter arrives. The pilot, a stocky guy named Jeff wearing camouflage pants and an Army sweatshirt, hops out and shouts hello over the roar of the rotor blades. He leaves the blades spinning as the group gathers equipment and loads it into the aircraft.
Remembering the online training course I was required to take before I came here, I know to expect a pre-flight briefing from the pilot before we set off–and since I am the only one who hasn't flown with him before, I get a quick safety lesson too. Jeff's briefing is brief, but covers the essentials.
"See that thing in back you can't see?" he shouts, gesturing at the rear rotor blade, which is just a faintly visible blur of indistinguishable length. "That'll ruin your day."
I remember the stick figure from the training animation that lost his head by approaching the vessel from the rear. I plan to take Jeff's simple advice.
I'm mostly thrilled to be joining this expedition as something like an embedded reporter to the mountain's restricted zone. But I do want to make sure I'm doing everything right–especially around the helicopter. After all, Katrin's email to me before the trip said, "Please make sure that you bring survival gear with you, in case we have to walk off of the volcano, or the helicopter can't get to us right away."
I get a few more safety pointers from Jeff and pretty soon we're ready to go. I climb in back with Peter riding up front. Katrin and Angie stay behind to hook the swing set onto a rope on the next flight. We lift off above them and then pitch forward, zooming over the armies of trees arrayed in rows reaching up toward the mountain. From the helicopter, the full scale of the mountain comes into view now–from the lower flanks all the way up to the rim. And then we're past the timberline and over the snow.
46.17370 N, 122.16150 W, approximate elevation 5,000 ft.
Southeast Slope, Mount St. Helens
On the ground, Jeff has to settle the skids of the helicopter into the snow before we can get out.
Upon getting the all-clear, Peter and I unload. The sun is fully up now, at least at this elevation, and the snow is sparklingly bright. Up at the rim of the volcano, the last of the clouds are clearing, and it's becoming more evident that much of the steam is coming from the mountain itself.
The helicopter takes off, and once the sound of its blades fades away, Peter and I are left with silence on the mountain. There is no wind and our footsteps are muffled by the snow.
Peter soon takes care of the silence. Digging out two generators that had been left behind on the last trip, he hooks up a power saw of some sort and starts grinding away at the rusted tripod monument that he will modify for use as the base for the GPS antenna.
The monument is left over from earlier efforts to measure surface movement on the mountain. It was installed in the early 1980s and used into the 1990s. Using the older technique, called electronic distance measurement (EDM), surveyors bounced beams of light from fixed locations on the mountain off reflectors on stations like this one. Electronic sensors then measured the travel time of the reflected light to determine the distance to the station and thus its position relative to others.
GPS technology has replaced the old system by registering distances to satellites rather than points on the ground. This system can be far more precise and can also be automated so that data can be sent off the mountain rapidly and streamed online, again using technologies that have only become available over the last few decades.
Of course, even new technologies have limitations. Just last night, the team was discussing trouble with the station on a ridge to the south that is used to relay communications off this part of the mountain. Apparently an animal got inside the fence of the relay station and smashed equipment there. We're having trouble using the radio Peter brought along.
I had the challenges of getting signals off the mountain–known as telemetry–explained to me before the trip by Mike Jackson, director of the PBO in Boulder, Colo. Jackson didn't consider it the most glamorous part of a site installation.
"The sexy part of it is going to stations and working high on the volcano," he says. "But where the rubber meets the road is getting the data from the stations back to someplace useful. It's real thankless work."
Jackson had also described to me what the first installation trip to the mountain was like–the one a few weeks before that was closer on the heels of the major eruptions. The excitement level was so high, he said, "You could have cut it with a knife."
Although they probably each had concerns, and one member felt more comfortable staying below at the staging area, they weren't always thinking about the volcano's activity.
Jackson notes some concern about breathing ash, especially in the high winds they faced that week. He isn't thrilled about the emergency plan to escape the ash by holing up in a sleeping bag and using it as a filter. "I'm a little claustrophobic," he explains.
The payoff for doing the work, besides the excitement involved, is that, once the systems work, they run automatically. These stations provide continuous records, unlike temporary GPS sites that must be collected periodically to retrieve data. The stations record their positions every 15 seconds and send data back to Boulder every hour for processing. Once the processing is complete, which is supposed to take less than a day, the data becomes available online–similar to the seismograph data of Mount St. Helens now available over the Web.
The prospects for getting all communications going today, however, aren't looking good at the moment. Perhaps as a result of the radio troubles on this side of the mountain, Peter can't reach Katrin at the base camp. He has realized he's missing some tools he needs to weld a plate on to the GPS monument. There's other gear missing as well–things they thought were left up here from the trip a few weeks ago.
While we wait for the helicopter to return, we find the batteries left behind on the last trip that have since been covered by snow. We also clear a place to put the swing set. Jeff delivers the swing set, lowering it down on a hook, but we can't get a message to him about the tools Peter needs.
Frustrated by the delay, Peter tries to take care of what he can and do some of the improvising he mentioned earlier. "I have to come up with a game plan," he says distractedly, almost to himself. But he is still thwarted from his main job of retrofitting the monument. When Katrin and Angie show up, Peter hops in the helicopter to rush off back to camp for the missing gear.
Early delays aside, it's a beautiful day. The weather certainly isn't causing any problems–in fact, the sun is getting hot. From our large, flat snowfield on the flank of the mountain, one can see Mount Rainier to the northeast, Mount Adams to the south, and even Mount Hood off in the distance to the southwest.
Below us there is a field of snow-covered volcanic rubble: dark rock under white that from a distance makes it looks like the top of a frosted oatmeal cookie. We're on the section of the mountain known as the "Worm Flows," named for the channels of churning lava that wove their way southeast in an eruptive period between America's revolutionary and civil wars. Over time the channels piled up on themselves, making this slope of the mountain more gradual than other areas. These days it is a telemarking ski route because of that.
The lava in the Worm Flows was blocky and unlike the oozing type of basalt lava one sees in pictures of Hawaii. It is more closely related to the blocks that built other tall volcanic ranges like the Andes in South America–in fact, the rock is called andesite because of that. Andesite has a higher silica content than does basalt, which is the key ingredient for making it less oozy. Thicker-flowing lava gets caught in vents more easily, and traps gases, too; both are recipes for explosions.
But there are no explosions today. When the generators aren't humming, the air is calm and peaceful, and without a view of the crater, the only reminder of how recently the volcano exploded is the plume of steam rising from the rim.
Here and there through the day, the radio crackles on (the receivers seem to have revived). We are not the only ones on the mountain, and we can listen in on groups in the crater and flying overhead radioing back to the main dispatch: the Cascade Volcano Observatory in Vancouver, Wash.
Since it's the first nice day in over a week, the U.S. Geological Survey is taking aerial photographs to check the growth of the dome inside the crater that has grown up since the activity of a few weeks ago. We're sharing use of the helicopter with this USGS group. Their news today is that this dome continuing to grow and move south, toward the back of the horseshoe crater; in fact, it's making its way toward where we're located.
The radio crackles. "Vancouver, do you copy?"
"Vancouver, we copy," says a voice in response.
"There are just about perfect conditions, so I would expect it'll only take a half hour for photos," says the first voice.
Everybody seems to be fairly optimistic on this sunny day.
Back at our site, however, there continue to be snags.
The welder isn't getting enough juice out of the generator, Peter complains. The conduit sheathing the cable between the power supply and GPS monument break and we have to rethread the heavy cable through another–a time-consuming, labor-intensive task.
A wire short-circuits at the power box.
A crucial bolt falls in the snow.
"Nothing's working the way we want it to," says Katrin at one point. Through the afternoon, nobody is particularly talkative–they seem focused instead.
But somehow the station is still coming together. The batteries are all hooked up to charge at the solar panel. Peter manages to retrofit the monument with the GPS receiver. We get the two connected with the cable.
"Talk about on-the-job training," Angie tells me at one point. "We should set one of these up in the office so I could tinker around with it."
The day wears on. The wind picks up and shifts so the plume of steam is now headed more toward us. The radio crackles again.
"Just to confirm for the eleven-hundredth time," says Vancouver. "We have a lovely steam condensation plume going ten thousand feet in the air, and no ash."
"No ash," says somebody closer to the crater.
"Thank you. We have some over-enthusiastic people reporting ash advisories."
Later, some group wants to squeeze in time to get rock samples from the crater. Vancouver tells them they don't want to interfere with Katrin's position. Our work is priority today for using the helicopter.
"Roger that," says Katrin, off-radio.
But time is running short. The issue with the power control box is unresolved. Also, Katrin needs to go to another site to make adjustments there we expected to get to earlier.
With the shadows creeping across the face of the mountain, Angie and Peter work to set stays to hold the swing set down for winter storms. Peter drills holes into nearby boulders in order to plant the cables. It's getting cold again and Angie keeps blowing on her hands to keep them warm.
To the south, the staggered rows of distant hills are blending together into a single silhouette horizon.
Jeff picks up Katrin in the helicopter and Peter, Angie, and I wind up as the last three people on the volcano for this evening.
It looks like the power control box can't be fixed for now, but this is a quick fix for another time–if the current weather holds, the team might get up here again later in the week. Plus, the rest of the site is installed, which is an accomplishment considering the snags the group has faced today.
The last thing we do involves mixing epoxy to fill the gaps around the screws holding stays to the rock. The three of us hunker around a rock Peter uses as a place to mix the quick-setting goo. We rush to apply the stuff with sticks we've gathered from the few dead trees in the area.
In the end, for all the power tools and satellite-linked electronics, the final touches to the GPS station on the southeast slope of St. Helens is completed using sticks and stones. Peter, who's until now hardly smiled through most of his stressful afternoon, manages a joke.
"Just another installation," he says. "With our state-of-the-art tools."
Epilogue: Since Nov. 3, 2004, five PBO GPS stations, including the one discussed in this article, have been transmitting data back from Mount St. Helens to the Boulder facility. The Cascade Volcano Observatory is using the data on a daily basis to assist in their monitoring efforts of the current volcanic activity..
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