Dust flux, Vostok ice core

Dust flux, Vostok ice core
Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Saturday, August 26, 2017

More Arctic landforms

More shots from a commercial flight (Toronto-Shanghai), which passed over the western Canadian Arctic, and eastern Siberia.

 Snow-filled drainage pattern on Melville Island, in the western Canadian Arctic.

Well-developed trellis drainage pattern on Melville Island.

The trellis drainage pattern results because the rocks are more easily eroded in some directions than in others. This can be due to bedding in the rock, or faults or other structural weaknesses. The pattern here is quite angular, which suggests faulting to me. Rocks undergoing compression tend to develop two (almost) perpendicular series of faults. 

There's also a rather deep-looking canyon in the above two pictures. Normally to get a canyon, you are looking at fluvial erosion over land that is experiencing uplift.Something more has happened here, as it is difficult to follow the canyon through the folded rocks of the Melvillian Disturbance just above the centre of the second photograph above. These rocks were folded and faulted prior to deposition of Late Permian sediments (~250 Ma).

Melville Island again, but I'm not quite sure what I'm looking at. It looks like some of the folded and faulted rock units of the Melvillian Disturbance.

This is over eastern Siberia. I'm really not sure what this is. My first guess would be a pingo, but given our altitude of 10,000 m and the focal length of this shot, it has to be well over 1 km long, which seems awfully big. Maybe it is an inselberg.

Some rugged terrain in eastern Siberia.

Looks like gossan. Who'd have thought there would be minerals in Siberia?

Don't be too quick to go out staking here. I don't see a lot of infrastructure.

Braided rivers in Siberia.

Thursday, August 24, 2017

Ice under cloud

Yesterday's flight took me north from Toronto, over Hudson Bay and into the western part of the Northwest passage, then over Melville Island and on into the Arctic Ocean.

These are digital photos from a commercial flight, with some post processing to balance colours.

Looking down through clouds at ice floes in the western part of the NW Passage.

I'm not sure whether the larger agglomerations of ice are parts of the ice pack that haven't broken up entirely, or are part of the multi-year ice that has broken free from islands or ice shelves..

Sea ice seen through a couple of holes in the clouds.

In the Arctic Ocean, we seem to have flown over an area where the ice hasn't broken up at all. We can clearly see frozen leads in the ice.

Monday, August 21, 2017

Dark sun

Well, I had another go at the question of digital vs film photography today, with filom coming out on top (somewhat retrospectively).

In 1994 (I think) we had a solar eclipse in southern Ontario, which I photographed with the old Nikkormat, a telephoto lens, and a teleconverter. I don't remember the details, but I'm pretty sure I was working with the smallest possible aperture setting and the fastest shutter speed. I remember aiming the camera just by using the shadow it cast upon the ground (easy as I had the camera on a tripod). Tragically, the time of totality was blotted out by cloud cover, but I did take a number of pictures as the eclipse progressed.

Scarborough, 1994

The above pictures were scanned from slides taken during the eclipse all those years ago.

Below is the best I could manage today. Of course, I left the DSLR in China, so this is really just a point-and-shoot camera.

I haven't managed any form of post-processing that makes the sun appear like a crescent, although the lens flare at the lower right does have the approximate shape that I obtained through a pinhole projection.

Sunday, August 20, 2017

Metals (updated)

Some gold and silver on display at Ottawa's Museum of Nature.

I've always like dendritic gold

Wiry native silver

Native copper

Had some problems with my SD card reader, and found a few more:

Another dendritic gold

Looks like a euhedral gold grain suffering from some wear.

Nice nugget

Wednesday, August 16, 2017

Emergency storage for Canada's gold

The Diefenbunker--a cold-war-era bunker built to house the Canadian government in case of a nuclear attack by the Soviet Union--has a deep vault which was intended to house Canada's gold reserves during just such an emergency. The bunker is in Carp, a small town on the rail line just west of Ottawa.

The vault is about 25 metres below the surface, and looks like it would make a pretty good discotheque. Obviously, there is no gold there now.

Behold! Canada's gold reserves.

The vault was to be guarded by an impressive vault door.

Changes in pressure could make it impossible to open the vault door, so they had a smaller door that could be opened in order to equalize pressure between the vault and the entry hall.

They also created a narrow passageway completely around the vault, so it was less likely to be damaged in an earthquake. The vault would have been guarded, but rather than walk around the vault, each corner had a mirror in it, so that the guard could see all around the vault from one place.

Welcome to the underground

The plan was to move the gold somewhere where it couldn't be irradiated. Maybe the thinking was that radioactive gold wouldn't be suitable as a monetary base. I'm not sure I agree. The velocity of money idea suggests that the faster money circulates, the better off the economy is, and if all the gold had been minted into coinage and pumped into circulation, I think the radioactive coins would have really circulated.

Anyway, I took a close look for Canada's gold reserves, but didn't find any.