[Conan the Librarian]

The next year the British sent an expedition to the arctic to look for the Northwest Passage. They found an open waterway almost all the way through, but, turned back fearing getting caught in ice.

Dust and soot from Tambora may have been the cause of this, as dark material will help ice to melt.

After that, it came back again.

[logi_cal869]

Dust and soot from Tambora may have been the cause of this, as dark material will help ice to melt.

Generally I might have agreed with that long ago (makes sense) . But nature's examples are quite different. http://entropyliveshere.blogspot.com/2014_08_01_archive.html

Scroll down to August 6, 2014 and see what I'm referring to:

We saw a lot of these black ice cones. Apparently the debris from the volcano serves to insulate the ice, so the ice under the dirt melts last (resulting in the cones). Our guide also told us that the early settlers to Iceland were afraid to come up onto the glaciers, because they were convinced these were trolls. I believe it.

Same thing happened back east. There's apparently still snow to be found under street debris that settled on the piles plowed out of streets of Boston.

Ah, found the link

http://www.usatoday.com/story/news/2015/07/08/snow-boston-seaport-district/29849439/