This RAPID award funds a prompt response to the ongoing, massive eruption of Tolbachik volcano, central Kamchatka, Russia, which started with little warning on November 27, 2012, after 36 years of quiescence. Within two days of the eruption onset the lava flows had already traveled nearly 10 km, covering an area of ~14 km2. The eruption has formed a series of cinder cones that feed lava flows, which at the time of this writing extend for nearly 20 km over the barren slopes of the volcano down into snow-covered forests. The investigators will join an international team of volcanologists who are monitoring the ongoing activity, and will focus on two important aspects of the eruption: (1) interaction of lava with snow and ice, and (2) temporal variations of the composition of erupted lavas and their crystal cargo.
Both of these topics are timely for improving our understanding of volcanic eruptions. Gaining a more quantitative understanding of how lava flows interact with snow and ice is critical for assessing hazards at snow and ice covered volcanoes and for improving our ability to recognize ancient deposits formed by lava-snow interactions. Few if any quantitative studies have been attempted in the field to quantify heat transfer from lava to snow or ice; this requires direct field measurements at the front of an active lava flow propagating through the snow/ice-dominating environment. While these conditions are highly ephemeral, they are now present at Tolbachik as the eruption began after much of the surrounding landscape had been covered by seasonal snow, which has created a unique opportunity to measure heat transfer between lava and snow/ice and provide more accurate constraints for experimental and theoretical modeling of their interaction. Having a better understanding of how lava flows rapidly melt snow and ice is important for identifying hazardous areas around snow and ice-covered volcanoes such as Mt. Rainier in the Cascades. Similarly, collection of lava and ash samples during and immediately after their eruption is important because: (i) their juvenile origin can be established unequivocally and (ii) their time of eruption is known precisely. These characteristics are critical for using a series of erupted products to observe compositional trends in the eruptive sequence and to identify magma processes that triggered and currently drive the eruption at Tolbachik. This RAPID award will allow sampling of the eruptive products before they are buried by ash or later lava flows.
The funding for this project was critical for documenting one of the most important volcanic eruptions in the past 30+ years: the 2012-13 Tolbachik eruption in Kamchatka, eastern Russia. Very few volcanoes, with the except of Kilauea in Hawaii and Piton de la Fournaise on Reunion Island,erupt large amounts of basaltic lava on a regular basis. However, the eruption covered by this grant, at Tolbachik volcano in eastern Russia, erupted large amounts of fluid, basaltic lava between November 2012 and August 2013 (see image 1). While the eruption happened in a remote location, and so did not put many people in danger, other large volcanoes in areas with higher populations (e.g., Cascades, Andes) have occasionally produced large lava fields as well. So the information learned about this eruption will help us to better assess future eruptions at many volcanoes around the world. The fieldwork funded by this research contributed several different types of basic information for recording the history of the eruption. We were able to collect fresh lava samples (see image 2) for studies of the how the chemical composition of the lavas changed during the eruption. We were also to take temperatures of the lava, which were frequently well above 2000 deg F (~1100 C), with both thermal cameras and temperature probes (see images 3 and 4). We also used GPS equipment to mark the positions of lava flows on several different days, so we could measure how quickly the lava flows were advancing. But most importantly for us, we got to watch lava flows 'eating' through snow! We know that lava flows can travel across snow for at least a short distance from eruptions at other volcanoes (Hekla, Etna) and from experiments (see http://vimeo.com/19260895). However, we did not know how far it could go before sinking into the snow, or how fast it would cause the snow to melt. When ice-covered volcanoes explode, they can create large floods from the melted ice (Mt. St. Helens 1980, Eyjafjallajokull 2010). So we wanted to see how quickly snow melted beneath the lava, and it the lava-snow interactions were dangerous. Fortunately, we only saw small, rare floods during our field visits (see image 5), although it did happen! We also saw some small explosions where thick lava flows collapsed snowpack and mixed with meltwater. While these events were very small, the snowpack at Tolbachik was rarely more than 4-6 ft (1.5-3 m) thick. If similar amounts of lava flowed quickly onto thicker snow or ice, the hazards might be more serious. One of the most interesting discoveries we made was that slow moving lava flows move underneath the snow, and 'eat' their way through snow blocks, sometimes even making 'snow domes' (see image 6). No one has ever reported seeing this before, but it seems likely to be something that happens during large eruptions at other snow/ice-clad volcanoes as well. While the lavas that flow on top of the snow do not really look very different from those you would find in Hawaii, the flows that 'eat' snow seem to be distinctive. They have shiney, glassy tops that form as the melting snow drips water on top of the upward inflating lava, making the lava cool into volcanic glass. We think that this unique glassy surface should be recognizable in older lava flows, and so in the future might allow us to go to older volcanoes and identify other lavas that had a snow diet. This, in turn, could allow us to explore whether or not eruptions at certain volcanoes happen more frequently during certain seasons of the year, or even identify volcanoes that were snow covered in the past, even if they are not today. This type of information eventually gives us more clues to understand how climate has changed in the past, by identifying new areas that were once covered by snow and ice at least part of the year.
