ARKHANGELSK, May 7. /TASS/. Scientists of the Federal Research Center for Integrated Arctic Studies of the Russian Academy of Sciences' Urals Branch (Arkhangelsk) for the first time studied seismic dynamics of glaciers in the Russian Arctic, the Center's Head of the Seismology Laboratory Galina Antonovskaya told TASS. By using seismic stations scientists can record processes in glaciers and forecast, for example, icebergs to improve the navigation safety in the Arctic seas.

"Cryoseismology is a new, actively developing direction to use seismic methods in studying seismic events related to the dynamics of ice and glaciers. In Russia, we are the first to start studying glacier dynamics in the Russian Arctic. In fact, we are laying the foundation for cryoseismic monitoring. The melting of Arctic ice changes weather conditions, complicating navigation along the Northern Sea Route," she said. "Thus, new data on the state and dynamics of glaciers is fundamentally important in forecasting climate change, and in practical aspect - in monitoring the ice situation in the Russian Arctic".

Specialists have analyzed data obtained over several years at a seismic station on the Severnaya Zemlya archipelago. It was installed in 2016 on the Bolshevik Island at the Cape Baranov ice base of the Arctic and Antarctic Research Institute. Russian Arctic islands have very few stationary seismic stations: two stations are on the Alexandra Land on Franz Josef Land and one - on the Novaya Zemlya. The equipment on Severnaya Zemlya has been installed to improve the accuracy of locating Arctic earthquakes in the Barents and Kara Seas.

Simultaneously, the equipment also records data related to processes in glaciers on land and in ice fields at sea. This data on the Russian Arctic has been analyzed for the first time. "We were recording quite strong local seismic events, that is, the events occurring near and on the Severnaya Zemlya archipelago. Thus, our goal was to determine the nature of those events: whether those are weak earthquakes or strong icequakes?" the expert said. With only one available station, this is difficult and requires major mathematical calculations. The Center's seismologists have compared their results with data obtained on Spitsbergen by the Unified Geophysical Service of the Russian Academy of Sciences and by foreign scientists. Several seismic stations operate there simultaneously to make sure scientists can distinguish processes in glaciers. For example, an iceberg breakaway, or an ice dome cracking or a breakthrough of an intraglacial lake wall.

Severnaya Zemlya is mostly covered by glaciers, and the study of processes within ice domes is of great practical importance. Seismic data can complement information from remote sensing, such as satellite images, and glaciology field data. "In my opinion, these are very significant and necessary data to forecast ice conditions. With an appropriate density of seismic network and continuous observations, iceberg formation can be predicted," the seismologist noted.

The Kara Sea freezes, and the seismic station records processes in the ice fields, which can be used also to assess the ice situation.

Arctic earthquakes

Scientists have collected data on earthquakes on Severnaya Zemlya for the first time. Over five years of observations, 73 seismic events have been recorded, where 45 events occurred on the Oktyabrskaya Revolutsiya Island. Here converge the Kara plate and the North Taymyr deformation zone. The earthquakes are not very strong, but they cause responses in glaciers, which lead, among other things, to the formation of icebergs. "We have identified the relationship between earthquakes and icequakes. We stress the importance of continuous seismic monitoring to receive important information about glacier dynamics," she added.

The problem is that there are very few seismic stations in the Russian Arctic, and they are far from each other - 1,500 or 2,000 kilometers. These distances do not allow accurate identification of quakes' epicenters, thus some events are not included in seismological catalogues. There are no seismic stations on islands east of Severnaya Zemlya, though that part of the Russian Arctic is more seismic than the western part. "The New Siberian Islands are very interesting from the seismic point of view, and that's why, of course, it is simply necessary to have several stations to assess the seismic situation. The Northern Sea Route is becoming a main transportation direction, and seismic data should be included in the assessment of its safety, in the monitoring systems that are being created," she said.

Before seismic stations had been installed in the Arctic, specialists believed the Arctic was aseismic, but this has turned out to be wrong. Additionally, methane emissions can occur in northern seas, and they are potentially hazardous for vessels. Those emissions could be also recorded by seismic stations. In order to develop a network of seismic observations in the Russian Arctic, the stations could be located at Roshydromet (weather) observation points. They have light, communication, and, most importantly, people who could repair the equipment whenever needed.

In the coming years, scientists will continue to study ice processes both at Severnaya Zemlya and at Franz Josef Land.