After an extensive summer break, I am back again to writing on the blog. Sorry for the long interruption! I hope you all had a nice summer (or winter, depending on which place on this planet you call home). I spent the last two weeks travelling around Central Europe and Northern Italy, where the thermometers were hitting 36°C on a regular basis. Considering this, it gives me great joy writing about a place that will never reach these kinds of temperatures (no matter how bad a job we are doing fighting climate change): the Lena River Delta.
A summer-time view of the delta. Image by NASA / USGS
The Lena River Delta is located on the coast of northern Russia, where – as the name suggests – the Lena flows into the Arctic Ocean, specifically the Laptev Sea. If you are familiar with our motifs, you will notice that great river deltas – where a river finally meets the sea – have some incredible potential for breath-taking satellite images. Just like for the Danube Delta and the Mississippi River Delta (make sure to check out my blog posts on those two) this is also true for the Lena River Delta.
The Lena is one of the three great Siberian Rivers. Indeed, the river is the 5thlargest of the world in terms of discharge. Vladimir Ilyich Uyanov, who you might know as Lenin, might possibly have taken his alias from the Lena, after he was exiled to Siberia at the end of the 1800’s, although there is no concrete proof for that. What is more certain, however, is that the Lena has created some incredible natural scenes right at the very end of its long route through Siberia. And these amazing sights, as seen from space, are at the focus of this blogpost.
The Lena River Delta extends far into the Laptev sea. The size of the delta amounts to nearly 30,000 square kilometres (roughly 12,000 square miles). About half of this area is designated as a natural reserve, the Lena Delta Wildlife Reserve, the largest protected areas within Russia. Indeed, 20% of the Russian Republic of Sakha – an area about the size of Western Europe) were designated as protected areas in 1996, known as Sakha’s “Gift to the Earth”.
The delta provides an important nesting ground for migratory birds. Image by Peter Prokosch, www.grida.no/resources/1783
One aspect that makes the Lena River Delta especially interesting as a satellite image motif are its incredible seasonal changes that take place every year. While the ground below the delta is permafrost - constantly frozen rocks and soil that extend down several hundred metres - its surface comes to life every year for a few months. Every May, the frozen Tundra is transformed into a lush wetland, attracting migrating birds and other wildlife. This transformation is especially magnificent when viewed from above. Take a look at the images below, one showing the delta as it looks most of the year, the other one showing it during the summer months. Besides the ice retreating from the delta, notice the difference in colour of the land mass!
Satellite images of the Lena River Delta taken in different seasons. Images by eoVision / USGS.
Generally speaking, what makes our satellite image motifs special (at least to us, but I hope to you too!) are often the motif’s unique pattern and structure (e.g. the loopy bend of our motif “Canyonlands” or the unique shape of our motif “Danube Delta”) or its colours (e.g. the amazing shades of blue of our motif “Sandwich Harbour”). The Lena River Delta is special, as it both exhibits amazing colours (white ice, dark blue water and brownish soil) as well as intriguing patterns.
There are two aspects of these patterns that make the Lena River Delta especially interesting. The myriads of little rivulets and ponds that riddle the delta, giving it this special dotted look. The water coming downriver is always looking for the easiest and shortest route its final destination, the ocean. As a result, the course of the small rivulets is constantly changing, making it extremely difficult to map the delta and its water ways.
Myriads of constantly changing rivulets and ponds riddle the Lena River Delta, making the area extremely difficult to map and navigate. Image by eoVision / USGS.
However, while these small, constantly changes rivulets are not unique to the Lena River Delta (you may recall my blog on the Mississippi River Delta), what is relatively unique about the delta are the strange patterns on its surface, also known as a polygon tundra (see image below).
The Polygon tundra of the Lena River Delta. Image by Peter Prokosch, www.grida.no/resources/1798
These strange patterns are created by a phenomenon called “thermal contraction”. Now, physics was not my favourite subject in school, but I will try to explain this process: During the winters of Siberia – due to extreme cold temperatures – thermal contraction cracks form on the surface of the ground, only a few centimetres wide but several metres deep. During the warmer summer months, the ice and snow covering the ground melts, filling up these cracks with the remaining water. Due to the permafrost just below the surface, this water freezes in turn and expands (as you might know from making ice cubes in your own freezer). This expansion causes the originally narrow crack to expand, turning it into an ice wedge. This process repeats over several years, turning the thin cracks into ponds that can reach the size of a swimming pool. These little pools can be found all over the delta, creating this incredible pattern.
These polygons are created through a physical process called "thermal contraction". Image by Peter Prokosch, www.grida.no/resources/1808
The location of the Lena River Delta in the northernmost areas of Siberia might lead one to believe that the place has little in terms of interesting history. Few would expect that the delta was in fact the setting of the final days in the life of many of the men of the Jeannette Expedition. In 1879, George Washington De Long departed with a crew of 32 from San Francisco on an Arctic exploration. After getting trapped in ice for two years, the Jeannette finally sunk on June 12, 1881. The crew started their march for safety towards an area on their map where they expected to find other humans: the Lena Delta. On their search for safety, the three rescue boats the crew used got separated. Only two reached the Lena River Delta, the third was lost and its crew was never heard of again. Of the other two boats, one’s crew successfully reached a settlement further down the Lena, while the majority of the other one’s crew died within the delta. Of the 33 men who left San Francisco in 1879, only 13 returned to the US.
The last days of the Jeannette expedition. Image by Norman Einstein, Wikimedia Commons
Polar expeditions going wrong seems to be a recurring theme in this blog. You may remember, in my blogpost on the Belcher Islands I touched upon the story of Henry Hudson.
If you are as fascinated as we are by the amazing beauty of the Lena River Delta, we invite you to take a look at our shop, where you can find the motif as poster and premium prints in various applications and formats.
And that's it for this blog entry. Please let me know how you liked reading it in the comments below! If you enjoyed it, please consider subscribing to our newsletter, in order to receive notification emails whenever we post a new entry here.
If you would like to read more about the Delta and see some amazing images of it, I highly recommend you check out the page of GRID Arendal.