How Not to Be Blown to Smithereens

By: | July 23, 2010
Searching for treasure with a metal detector

Last week a British treasure-hunter, Ian Snook, barely escaped a rather unpleasant end when his metal detector began clicking madly on a beach in Dorset, England. Answering the siren call of potential loot, Snook began digging furiously, only to find a battered metal sign. It read “Precaution–bombs fire instantly on breaking in air. Stringent precautions must be taken to avoid cracking during handling–the caps must never be removed.”

Below lay 24 World-War-Two glass bottles filled with deadly phosphorus and benzene.  The British Army had buried these grenade-like weapons 70 odd years ago to dispose of any Nazi landing craft.

The faded sign, with its words of clear warning, prevented Snook from accidentally blowing himself to smithereens.  And that’s good: while I am not particularly fond of treasure hunters, I wouldn’t wish this fate on anyone.  But this little news item got me thinking.  How on earth are we going to warn future generations of archaeologists and other curious types from digging in similarly toxic sites 1000 years from now, or even 10,000 years from now? Continue reading →

Heather’s earthquakes vs. Ann’s: choose Heather’s

By: | July 22, 2010
magnitude 3.6 Baltimore earthquake, 7/16/10

At 5:04 on the morning of July 16, 2010, I woke up because the bed was vibrating, as was the floor.  A small rumbling noise moved through the room and on out, and I thought, “earthquake,” and went back to sleep.  It turned out to have been a magnitude 3.6 – pretty big for these parts.

Heather, however, lives in the Pacific Northwest, in the Cascadian subduction zone where a little tectonic plate named Juan de Fuca slides under the western edge of the enormous North American plate.  Plates don’t slide under other plates without drama, and around 300 years ago, Cascadia had what was probably a magnitude 9 earthquake; the magnitude scale tops out at 10.

BKS.LHZ_.92.04.25
mag. 7 earthquake in Cascadia – 04/25/92

Cascadia has had lots of non-negligible earthquakes since, so geologists pay attention and most recently, have sunk an array of earthquake sensors in the ground above the subducting plate’s leading edge.  Along that edge, swarms of small tremors happen, hardly noticeable, but geologists think that understanding those tremors might help predict big earthquakes.

little tremors under Cascadia

The reason they think that is, while the plate’s leading edge is pushing under North America, the part of the plate farther that’s back, under the Pacific ocean, is stuck, locked in place; and sometime in the next century it should come unstuck and trigger another huge earthquake.  So geologists are watching for those little seismic events — they look like the little cardiac events before the big one.

I, luckily, live in Baltimore which is right smack in the middle of the large, stable North American plate that runs to the middle of the Atlantic — and is immune to such cataclysmic goings-on.  Except when it’s not. Continue reading →

Shrimp on Prozac

By: | July 19, 2010

Alex Ford contemplates a medicated shrimp

At least 40 million people worldwide have been prescribed Prozac, but how many of them know that they may be sharing their medication with a crowd of shrimp? The poor shrimp aren’t any happier, either: the antidepressant prompts them to swim upward toward the light, which makes them more likely to be eaten by predatory fish or birds.

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A Summer Science Poem

By: | July 13, 2010
Sunny Side Up

It’s summer. The perfect time to fry an egg on the sidewalk. Or, if that proves too taxing, just flop onto the grass and watch all the little invertebrates toiling away: an ant carrying a crumb or a seed, a beetle scurrying over grains of sand, a grasshopper leaping. Beneath the surface is a vast city of small creatures: insects, spiders, springtails, nematodes, earthworms, lichens and fungi, and as many as 10,000 to 50,000 species of bacteria per gram of soil.

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