Geo-Joint: Streets with no Names

Living in the USA, you grow up with street names. The name of the street you lived on when you were just a tyke may have been among the earliest names you learned, so that Mom could hope to get you back if you wandered off and were found by a friendly policeman. Just like people, streets have names, or … Read More

Geo-Joint: Underwater Logging

Logging is one of the most dangerous jobs you can do. Knocking over big heavy things using sharp running power tools on slippery slopes and dragging them to somewhere else using heavy equipment – what could go wrong? However, even if done injury-free, unfortunate circumstances can hinder the operation. In logging’s older days, felled logs would be dragged down to … Read More

Geo-Joint: Remarkable Rivers

Water flows downhill, and takes the easiest path that gravity pulls it along. Depending upon the kind of geography and geology in a drainage basin, that stream course will develop its own individual qualities, from sculpted rocks, to unique water chemistries, to particular plant assemblages. The Cristales River, or Caño Cristales, in Colombia is one such “special circumstances” river. Its … Read More

Geo-Joint: Magnetic Pole Reversal

Way back in 1906, a French geologist named Bernard Brunhes made a fascinating discovery. He knew that previous studies had shown that baking pottery or bricks caused iron particles in the clay to align in a north-south orientation. Heat of sufficient intensity causes the electrons in iron to go into a high-energy state and become “looser,” facilitating realignment. In studying the clays over which lava had once flowed, he found that iron particles in both the lava and the baked clay underneath it had the same orientation. Then further study in places where there were multiple layers of lava showed that different lava layers had opposite alignments. The only logical explanation was that, amazingly enough, the magnetic poles of the earth must be periodically reversing.

Geo-Joint: Foreign fruit


Suppose someone offered you a Chinese gooseberry. Or a carambola. How about a slice of durian? Some jackfruit? Care for a rambutan? What? These are all fruits from faraway places, some of which you may have tried, but probably don’t consume as much as you do apples, oranges and grapes. It’s a good bet you’ve had Chinese gooseberry, but not by that name. It was a fruit imported from China to New Zealand in 1904. People thought its flavor resembled a gooseberry (and of course we all know what those taste like) so “Chinese gooseberry” was a logical name. The names “mihou tao” or “yang tao,” as the Chinese called them, didn’t roll off the New Zealander’s tongues quite so easily…

Geo-Joint: St Anthony’s Falls

Asian carp

St. Anthony’s Falls raises and lowers the barges five stories by the usual means of flooding locks with river water and it has some uninvited guests. Read more….

Geo-Joint: Planet X

For the longest time, we were all taught that there were nine planets in the solar system. From closest to, and farthest from the sun, they were: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Sadly, Pluto fell off the list when astronomers determined that its small size and failure to fulfill all the gravitational functions of a bona fide planet disqualified it. So we were down to being eight fellow spheroids in our neighborhood, commonly known as the Solar System. Recently, however, two astronomers (one of whom made the case for Pluto’s ouster) have postulated the existence of a replacement ninth member, one that’s in the club but doesn’t come by for a meeting very often…

Geo-Joint: Greenland’s Hidden Canyon

Greenland's Hidden Canyon

The Earth has some huge canyons and they’re pretty easy to spot. A couple of years ago, scientists found a great big one that’s never been seen before. Where’s it been hiding?

Geo-Joint: Sea Level Changes

Sea level changes

When was the last time you sat down into a hot bath and the water was up to your chest, but barely covered your anklebones? That just couldn’t happen, given what we know about liquids flowing to conform to the shape of their container. But the rules change, or get more complicated, when you get to a container the size of an ocean basin. Because of these changed circumstances, some parts of the world are already suffering from sea level rise, and others are barely aware that it’s happening.

Geo-Joint: One Hail of a Story


Fat raindrops can kind of smack you in a tropical downpour, but it’s not painful. Snow is downright gentle, although in a blizzard it probably hits with some cold force (I wouldn’t know, having lived most of my life in the southern half of coastal California). But hail is another story. Most hail is pebble-sized and just sort of bounces off, but the mechanics of making hail can allow it to grow to truly frightening proportions.