Geo-Joint: Lake Michigan’s Overdeveloped Mussels

Some lakes are known for their stunning clarity, while others are as green as grass, from bright green to dull olive. Lake Tahoe has long been extolled for its deep blue color due to the clearness of its water, although over time it has diminished, and the pressures of development, sedimentation, fire, and more, mean trouble for its future. Most … Read More

Geo-Joint: Lunar Origins

 Everybody knows that people get crazier when the moon is full. And more babies get born then. And the moon is hollow, and full of aliens. OK, maybe none of that is true. But the moon surely makes the tides go in and out and helps birds and moths navigate, and tells grunion when to spawn, and encourages sweethearts to … Read More

Geo-Joint: Iceland’s Cool Story

The Geo-Joint recently prattled on about the grand phenomenon that built the Mid-Atlantic Ridge. Though it would be quite a sight, most of its very long, sinuous outline is well undersea and out of viewing range for tourists. A striking exception to this is the little country on the sizeable island called Iceland. Iceland is built of the magma rising … Read More

Geo-Joint: Venice—Treading Water and Waiting for a Life Preserver

The origins of Venice are rooted in simplicity and desperation. Simple, because the earliest inhabitants of the many lagoon islands at the northern end of the Adriatic Sea were those making a basic living off the sea—fishermen and sea salt miners. But as the Roman Empire came under attack by invaders from the north, desperation became a motivation. People from … Read More

Geo-Joint: Continents Drifting Toward Plate Tectonics

Anybody with half a brain idly spinning a globe will notice that the coastlines of eastern South America and western Africa are pretty similar. And that’s just the most obvious coastline match-up, of which there are many. It has always seemed like a logical notion that the two continents were at one time connected, but then there’s that part about … Read More

Geo-Joint: Lava Tubes—Hot Conduits and Cool Caving

The Hawaiian Islands are built of lava. Some of it is fresh and flowing, some of it is cooled, some eroded into pebbles and soil, but it all started as molten lava. The first thing a tourist learns, especially if they are visiting Hawai’i Volcanoes National Park on the Big Island, is that there are essentially two forms of lava … Read More

Geo-Joint: Movin’ the Mighty Mississip’

Rivers flow where gravity pulls them, and they effortlessly seek the easiest path. In steep mountain canyons, they tumble down sharply defined channels—there’s no doubt of their course. But when the land is flatter, it’s a good deal easier to influence that fluvial path. As a river meanders through territory of low relief, its course may wander back and forth … Read More

Geo-Joint: Shipbreaking in Southern Asia

From the beaches of Santa Barbara you can see them anchored a half-mile offshore: giant, white, floating boxes called cruise ships. They are enormous, but nothing compared to the behemoth tankers and container ships that ply the ocean road between the mainland and the local Channel Islands. Though they appear tiny on the horizon, their astounding size is evidenced by … Read More

Geo-Joint: Northern Ireland’s Peace Walls

Robert Frost sagely noted that good fences make good neighbors, an admission that keeping a healthy distance and clearly marking my territory versus yours can keep trouble from starting. It developed kind of the other way around in Northern Ireland. In the early part of the 20th century, forces in Ireland banded together to fight for Irish independence from the … Read More

Geo-Joint: The Enduring Bristlecone Pine

There are a lot of ways to establish records. Hairsplitting a category can make for multiple “biggest” or “tallest” or “oldest” of whatever. Just ask Guinness—it keeps them in business. So it is with the oldest living things. There are various kinds of organisms, even if you narrow the categories down to just trees. We’ll save some of the other … Read More