The Visible Earth, courtesy of NASA

Check out the Visible Earth collection of satellite images and map projections, created by scientists from NASA and around the world.


England, Great Britain, United Kingdom, Commonwealth…

What’s the difference between England, Great Britain, and the United Kingdom? A rapid-fire video explains all.

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Spot the Canadian Shield!

This map is from One Geology.

Hat tip to Ontario-geofish.

New outdoor game: geohashing

The comic xkcd suggested way to construct a daily location for each 1 degree of latitude and longitude, where enthusiasts can meet up. I’m getting ahead of myself, so I’m going to quote the wiki:

xkcd comic #426, published on 21 May 2008, contains an algorithm that generates random coordinates around the world every day. Everyone in a given region gets the same set of coordinates. As such, these coordinates can be used as destinations for adventures, à la Geocaching, or for local meetups.

Every day, the algorithm generates a new set of coordinates for each 1°×1° latitude/longitude zone (known as a graticule) in the world. They are randomly placed — they could be in the forest, in a city, on a mountain, or even in the middle of a lake! You can use this wiki to document the daily coordinates (geohashes) you’ve been to.

Unless you can accurately predict the stock market down to the penny, you can’t figure out what the coordinates will be ahead of time. You can first calculate a weekday’s coordinates at about 9:30am ET, and on Friday you can calculate the coordinates for each day that weekend.

When visiting geohash locations, please respect the area you are visiting. Absolutely do not litter or otherwise disturb the natural integrity of the area. However, if possible, creating some kind of a marker out of nearby materials (i.e. cairn of stones, … ‘stick figures’, etc.) is encouraged….

Official xkcd meetups

Official xkcd meetups happen every Saturday afternoon at that day’s normal geohash coordinates. All meetups start at 4:00pm* (local destination time). If you go at these times, you might encounter other readers of xkcd. Bring games!

In such cases when it is unwise to attempt to access the generated coordinates, the Saturday meetup is postponed until a day when the algorithm provides a more suitable location. Alternatively, when the coordinates fall within a body of water, you can rent a boat and win the Water Geohash achievement.

“Distressingly normal corals”

Highly Allochthonous has an article, “Distressingly normal corals found in nuclear basins.” They’re talking about the hardier corals re-populating the atoll at Bikini.

lagoon corals at Bikini, former nuclear test site

Satellite image revealed the lost city of Ubar

In 1991-2, satellite imagery revealed the lost city of Ubar. “The radar had seen right through the sand as if it were a sheet of glass to reveal streams, riverbeds and formations of a bygone age. SIR had photographed a vanished land.”

This image taken from space is further confirmation of the site of the lost city of Ubar. It is a radar image of the region around the site of the lost city in southern Oman, originally discovered from space in 1992. This image was acquired on orbit 65 of the NASA Space Shuttle Endeavour in 1994 by imaging radar and covers an area about 50 by 100 kilometres of the Arabian Peninsula. The prominent magenta colored area is a region of large sand dunes. The prominent green areas are rough lime stone rocks that form a rocky desert floor. A major wadi, or dry streambed, runs across the middle and is shown largely in white. The fortress of the lost city of Ubar is near the wadi, close to the center of the image. The fortress is too small to be detected but tracks leading to the site appear as prominent reddish streaks. These tracks have been used in modern times but field investigation showed many were in use in ancient times as well.

Global Flood Archive: 1985

The global map of major floods for 1985 was updated in April, 2002:

Floods, world map, 1985

It is available in larger size from the University of Dartmouth Flood Observatory. The charts describe the floods, keyed to their numbers on the map.

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