Archives pour l'étiquette spring 2014

Samples

Samples

The samples travelled 1400km upstream from the Igarka permafrost museum to Krasnoyarsk Federal University. This is the end of the intensive sampling of the Ienisei. Thanks to every single people who helped in this initiative: Virginie, Marie-Jo, Annick, Stéphanie et l’équipe d’ULISSE, Elena (our special agent in Krasnoyarsk), the Geocryology Laboratory team and particularly Anatolii and Nikita. Finally a collective thank to Igarka people who helped in any way to make this sampling possible!

Igarka

Wind

We are at the very end of the intensive sampling period of the Ienisei. Finally, “sampling on ice” was easier than sampling on water. Indeed strong winds made the sampling impossible during several days. It is impressive to see waves of several meters on the river. We still managed to sample and are confident on having a good record of the spring flood.
Allison left for Krasnoyarsk then Tura yesterday.
Today, 3rd of June, polar day and…snow…a classical question here: “when can we say that was the last snow of the season or the first one of next”.

Iceberg

Recession limb

We reached the peak discharge last week, and are now on the decreasing portion of the hydrograph. We managed to sample again yesterday on a fishermen boat. Ice is still present on the river but much more sparsely. As of yesterday, the Igarka branch of the Ieniseï is also now free of ice, making access to the river easier. We have obtained a very nice record of fDOM from our hand-held multiparameter sonde.

fDOM2

Ice blocks

What is next?

New hovercraft ride today but it turned on a Ieniseï branch visit: from the city to the kombinat. No access to the river today. Southern winds push the ice against our bank and it is still too dangerous to make a try. Anatolii said that maybe tomorrow we will have an opportunity. Multi parameter sonde gives us a very nice record of fDOM and we are eager to know what will happen with the next sample…

fDOM

Chaos

May 23: Grounded and Flooded

Although the main channel of the Ieniseï is ice-free, millions of tons
of ice are stuck along the banks, making them impassable for a
hovercraft or a boat. We have to wait. At the same time, the water is
rising and its level has increased more than 20m in the last few days.
The Island is now flooded, and the water level is reaching the first
cabins in southern part of the city. The local experts say it’s a huge
flood, but not an exceptional flood one.

DOC concentration

May 19: We got it

This very unique sample was taken in the middle of the ice break! Thanks to the talent of Sacha, “god of pilots” in Igarka according to Anatolii, we were able to collect another Ieniseï sample.Although the anticipation for reaching this sampling point was high, finding a way to the main channel was easy for Sacha, as he avoided huge ice ridges, played with water currents, and stopped the hovercraft on the shelf of the ice right above the sampling point with ease. The result was that we collected the most colored sample ever on a major Arctic river. A perfect sampling day (and very happy researchers)!

Bad guess

We made an educated guess, but we lost. Sampling an Arctic river during the spring freshet can be tricky! Based on satellite imagery of the ice movement, were expecting ice break to occur between the 18th and 20th. As the snowmobile sampling stopped the 12th, we decided to go sampling with hovercraft on Friday 16th. Bad guess, the ice break started at the very same time! But it lasted for only 24h and now we are stuck with “stable chaos”, and no sampling opportunity. Sampling natural environments (and custom clearance) teach you patience…

Icebreak21

May 16: Ice break!

We didn’t manage to reach the sampling site today because of…ice
breaking: a huge ice ridge closed the Igarka side channel’s access to
the Ieniseï main channel.  Further along the main channel, ice began
to move quickly this morning. In a moment, the river became a total
moving chaos, with the start of millions of tons of ice making their
way downstream. From the equilibrium of yesterday to today’s chaos, it’s a fantastic phenomenon we were fortunate enough to have the opportunity to observe.