Midsummer farce in the Arctic: Greenpeace flees ice "way thicker than anything we can break"

Climate Rescue Weblog

The helicopter gets off the deck at 0800. The ship's main engine starts 20 minutes later.
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The Arctic Ocean pack ice has invaded Nares Strait. It is old (called multi-year) sea ice, and averages six meters thick. This is way thicker than anything we can break with Arctic Sunrise. So before it can trap us in Hall Basin, we escape south. The crew all walks around telling each other that this is good, as we are all bored with Petermann.
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The sea ice is chasing us into the bay of large icebergs. The east side of Kane Basin is the Humboldt Glacier. Being a grounded glacier, the pieces that break off are huge. As a result, Kane Basin is littered with icebergs. There are maybe 70 that we can see from here. It's a real contrast to Petermann, where the glacier is floating. From a distance the glacier ice breaking off from Petermann does not seem very different from the sea ice that forms over the winter. But these icebergs from Humboldt are ten to twenty meters high.
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For the first time in this trip we do some real icebreaking. The ice is mostly first-year sea ice, sprinkled with pieces of glacier ice, which is much harder. It does not look very thick, and seem to be 50% melt pools, some of which go right through. At first, it is pretty easy going. With 90% power on, we are just able to break through the 50cm ice. Then we have to stop, back up one ship length, and charge at it again. And again. And again. As we cut alongside a large ‘berg, I understand Arne's explanation of ice under pressure. Here is ebb tide is pushing the floating sea ice against the grounded berg. The ice stops cracking ahead of us. We have to back up every boat length, and ram it again.

This explains Arne's first rule of icebreaking. Avoid it. Always look for a lead or a way to get around it. Icebreaking is time consuming and sucks down tons of fuel.