November 29, 2023

A Journey Into an Alaskan Volcano

A Journey Into an Alaskan Volcano

by
Jasper Baur|September 14, 2021

The rim of Cone D– inside the Okmok Volcano caldera– with the blue lake in the background. Credit: Nick Frearson
Im composing this note from the Steadfast; an old 108 feet long crabber boat equipped with a helipad, crane, 5 state spaces, kitchen, living room, 2 skiffs, and a science laboratory. The ship was obtained by the Alaska Volcano Observatory and renovated to work as a research vessel for helping in volcano monitoring and fieldwork. The Steadfast has a calm charm to it and is efficiently run by Captain John Whittier, deckhands Angus and Mark, Kait the engineer, and Robert the cook.
The reason I discover myself on this boat, anchored along a blurred border between the Bering Sea and Pacific Ocean, is due to the fact that I am a Ph.D. student at Columbia Universitys Lamont-Doherty Earth Observatory studying volcanology. I am dealing with the AVERT (Anticipating Volcanic Eruptions in Real Time) job lead by Dr. Terry Plank, Dr. Einat Lev and Nick Frearson. The objective of this task is to study two volcanoes in the Aleutian Islands off of Alaska by deploying an advance range of instrumentation that will transmit data through satellite in real time. This information will provide scientists the means to prepare for a volcanic eruption prior to one happens.
Jasper strolling towards the base of Cone D. Credit: Társilo Girona
The exploration has been an unbelievable mesh of brand-new landscapes, modes of transportation, people, and experiences. For beginners, this is my very first time in Alaska. It is also my very first time living on a research study vessel, flying in helicopters, riding an ATV, eating fresh halibut captured that really afternoon, and being chased by a herd of bulls. While all of these firsts are stories unto themselves, on July 15th, I entered my first caldera at Okmok Volcano on Umnak Island located roughly 4,200 miles far from New York in the Aleutian Island volcanic chain. When the ground collapses above a magma chamber, a caldera is a big anxiety at the top of a volcano formed.
Okmoks caldera is remarkably large; a crater that covers over 6 miles in diameter from rim to rim. The eruption that produced Okmoks caldera in 43 BCE was so huge that scientists argue it was a prospective consider the collapse of the Roman Republic, inducing a volcanic winter season that added to crop failures, famine, and disease. Inside the caldera, there are 6 smaller volcanic cones, marking where magma and ash from the depths of the Earth breached the surface area in the past. Although the last time Okmok emerged remained in 2008, it is still thought about an active volcano and is anticipated to erupt again in the near future. Throughout the 2008 eruption, it produced an enormous tuff (ash) cone named Ahmanilix, that beings in the northwest region of the caldera.
The goal of todays mission was to go inside of Okmoks caldera and take measurements of co2 along a strolling transect. In some cases, volcanos let out excess gas in the surrounding area. This process is called diffuse degassing. Dr. Társilo Girona, one of the researchers on the journey, and a teacher at University of Alaska Fairbanks, wished to investigate whether these areas of excess gas correlate with an increase in volcanic activity. My job was to help record the measurements, take water samples of the blue lake situated in the caldera, and assist Girona with soil temperature measurements.
After taking a helicopter flight from the Steadfast over the scenic island, passing over wandering cattle, rusted out WWII bunkers, and yellow wildflowers, we made it to the gates of the caldera. The gates of Okmok are essentially the drain system of the volcano, where a big stream called Crater Creek cuts through the 2500 ft rim, offering a cinematic and hassle-free path into the caldera.
Today we were lucky, and the caldera was only clouded on the south side, providing us the chance to complete our planned transect between the blue-green lake and the murkier sediment filled lake to the base of Cone D (the volcanic cone situated right next to Ahmanilix).
When the helicopter left, we wasted no time at all, condensed our packs, and started treking towards our target. The easiest route to the base of the cone was through a stream bed that weaved right in between the two lakes. After about an hour of hiking we reached the intersection of the base of Cone D and Ahmanilix, where we began collecting information for our walking transect.
Expedition member Társilo Girona strolls with the CO2 accumulation chamber. Credit: Jasper Bauer
Possibly the most stunning feature I experienced inside the caldera was the deeply incised gullies wearing down the ash cones. Ahmanilix, which is a simple 13 years of ages, was so deeply incised with dendritic (vein-like) patterns that it appears as though the cone has been in presence for thousands of years. These erosional functions illuminate the fight between volcanic forces with rain, wind, and snow in shaping the caldera morphology and how, over time, even volcanoes can be eroded away.
At each stop, we pressed a metal cylinder into the ground to make an air tight seal that decreases climatic influences in order to catch the getting away gases of the caldera. This specific type of measurement has never been done at Okmok so we were not sure what to expect.
After the transect was complete, we examined the signatures in the ships laboratory and didnt find anything unusual. Despite the non-groundbreaking findings, nevertheless, preliminary diffuse gas measurements are still crucial to supply a baseline for the future.
After the information was gathered, we needed to rush back to the helicopter drop off area, making certain to avoid the wetter, quicksand ridden areas near the edges of the lakes. We successfully finished the objective and boarded the helicopter, flying back out through the gates towards the Steadfast. I had a warm meal on my mind, and an unbelievable first caldera experience under my belt. Studying volcanos this last year, particularly lava streams and volcanic plumes, made the trip into the caldera even more unique, and brought to life the numerous hours of reading and online classes attempting to describe volcanic systems and their transcendent functions.
Ahmanilix cone seen from the northwest. Credit: Nick Frearson

While all of these firsts are stories unto themselves, on July 15th, I entered my first caldera at Okmok Volcano on Umnak Island located roughly 4,200 miles away from New York in the Aleutian Island volcanic chain. A caldera is a large depression at the summit of a volcano formed when the ground collapses above a magma chamber.
The gates of Okmok are essentially the drainage system of the volcano, where a large stream called Crater Creek cuts through the 2500 ft rim, providing a cinematic and hassle-free path into the caldera. These erosional functions brighten the battle between volcanic forces with rain, wind, and snow in shaping the caldera morphology and how, over time, even volcanoes can be deteriorated away.
Studying volcanos this last year, particularly lava streams and volcanic plumes, made the trip into the caldera even more unique, and brought to life the countless hours of reading and online classes trying to describe volcanic systems and their transcendent features.