At about 4am the other morning the ship started to slow down for a CTD station (salinity, temperature and depth measurements of the water column). We were stopping east of the Severnaya Zemlya islands for what was the last station of a section across the slope and along the shelf near the islands. A quick glimpse through the window resulted in an even quicker decision to put on clothes and rush to the deck, quietly so as not to wake up anyone sleeping in their cabins. But what waited outside was too amazing not to be shared: Icebergs, bergy bits, growlers, all around us. Even a glimpse of the islands. And sunshine! The quiet and calm of the morning combined with being still half asleep created an almost magical experience.
Glacier ice, or “ice of land origin”, as it is formally known in ice identification nomenclature, floating in the ocean is classified into different categories depending on its size and shape. The more time the glacial ice remains in the ocean and is moved about by wind and waves, or pushed into other pieces, the more it cracks, crumbles, rots, or becomes smooth. There are names for many different forms and features of the ice. The smallest ones are called growlers (because that’s the sound they can make when colliding with a ship and also because sometimes they are just beneath the surface and go unseen until making contact); somewhat larger pieces are called bergy bits; and in order to be classified as an iceberg, glacier ice needs to stand more than 5 meters above sea-level and be at least 15m long. We have seen tabular, wedged and irregular bergs, and bergy bits that came in so many shapes, but that also might have to be classified as irregular.
-Marika Marnela
In this photo, you can see just how many bergy bits and small bergs were afloat in the area where the ship stopped. The ice team leader onboard from the Arctic and Arctic Research Institute (AARI) in Russia identified the source of the ice to be from the northern and central islands of the Severnaya Zemlya archipelago, and said that most of the ice enters into the Laptev Sea to the east of the islands, rather than to the west into the Kara Sea.
Notice the diagonal dark stripes in the irregular bergy bit in this photo. Those lines are composed of very fine sediment from the island where this ice formed. At its highest point, the ice is about 3 meters (9 feet) out of the water and it has been exposed to a lot of weathering (melting and aging) which now gives some areas a smooth surface.
The curious structure of the tabular berg which looks a bit like cauliflower or mangrove tree forest, is actually ice that is a couple of meters high (about 6 feet) and has been washed so long with waves that the weaker areas of ice have rotted away.
The Canadian Ice Service has produced a helpful ice observation manual (for details MANICE: Manual of Standard Procedures for Observing and Reporting Ice Conditions) which included the attached figure 2.3 of different iceberg sizes along with references to common things like bicycles, stadiums and skyscrapers.
Wonderful photos!
Hi Ludus, they are so beautiful, aren’t they? It’s kind of like an ice sculpture garden!
Have any underwater waterfalls been discovered in the arctic? Do they affect the glaciers or animals? How deep can they go?
Hi Joseph, according to a couple scientists onboard (I asked around because I was not sure of the answer), there are known to be “cascades” in the Arctic, which happen when dense water from the Siberian Sea starts to cascade down the sea slope. It is rare that this water is dense enough that it reaches the bottom of the ocean though. As far as affecting animals, cascades definitely affect microscopic organisms such as plankton, which are “drifters,” meaning that they just go wherever the water takes them! 🙂
Hi Lindsay, what is the difference in minerals between the Arctic and the Mediterranean Sea?
Dear Shannon – a scientist onboard, gave me a fun fact in answer to your question: the different ratios of the 10 main components that constitute up to 98% of ocean salt is identical. But even though the composition of the salt might be almost identical, the Mediterranean is saltier than the Arctic.
Hey Lindsay!
What are the benefits of having Icebergs in the Arctic Ocean and some weaknesses of having them in the Arctic Ocean? If all the Icebergs melt in the ocean, due to Global-warming would it affect the climates throughout the world?
Hi Ke’Von, right now the climate is changing, as we know, and the decreasing amounts of annual sea ice over the last several decades is an indicator of that. There are several benefits of sea ice, which is the kind of flat ice formed on the surface of the ocean (icebergs are chunks of ice that have broken off glaciers on land and drifted into the ocean). The first is that it is a habitat, and crucial to the survival of wildlife such as polar bears, seals, and walruses, who use the ice to hunt for food in the ocean or rest and have dinner after catching dinner. Another reason is that ice is white, and reflects some of the Sun’s heat. As the ice melts, because the climate is warming, then the darker ocean will absorb more of the Sun’s heat (just like a black t-shirt absorbs more heat and makes you feel warmer in the summer than a white-t-shirt would). This would only cause more warming. And the cycle continues. Another reason is that the entire world is connected by climate, because the oceans and atmosphere are all connected. So what affects one place, affects another. So those are just some of the reasons why the melting of Arctic ice is definitely a negative thing.