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Showing posts from May, 2018

North America in the Age of Dinosaurs

A fabulous array of dinosaurs ranged across North America during the Mesozoic era. Descendants of ancient reptiles, dinosaurs had evolved as continents shifted, climates changed, and plants blossomed into modem forms. Diverse in size, shape, and behavior, dinosaurs faced no animal challenge. Yet none survived an end-of-era cataclysm. Perhaps they perished after a gigantic asteroid flung enormous amounts of pulverized rock into the atmosphere. The global cooling and darkness that likely followed are prime suspects in the snuffing out of flying reptiles, scores of marine creatures, and the lost lords of the earth. Great sun-warmed seas covered much of the earth during the late Cretaceous, a time of mild climates and ice-free polar regions. Densely forested with sequoia-like trees, Alaska felt winter's chill but saw little frost. The Western Interior Seaway, almost a thousand miles wide at times, flooded one-third of North America. The modem Gulf Coast was underwater, a huge bay s...

Which Energy Source is the Safest?

Energy use is a necessity in the modern economy, but the practices of extracting and using energy also create a deadly trade-off. NUCLEAR IS SAFEST Even including Chernobyl and Fukushima incidents, nuclear is the safest power source per TWh (90 deaths per 1,000 TWh). A BRIGHT FUTURE There are still some deaths attributable to renewables such as accidents and via lifecycle analysis, but they are among the safest forms of energy on earth (Solar: 440 deaths per 1,000 TWh, Wind: 150 deaths per 1,000 TWh). WATER DAMAGE Hydro is normally very safe, but it has one extreme outlier that skews the data (1400 deaths per 1,000 TWh). In 1975 the Banqiao Dam in China collapsed during a typhoon, killing 171,000 people. BLACK DEATH When the human and environmental costs of coal are added up. It's the biggest killer of any energy source by far. Air pollution alone in China kills over 4,400 people per day (Coal: 100,000 deaths per 1,000 TWh; Oil: 36,000 deaths per 1,000 TWh; Gas: 4,0...

Density Gradien of Native Palm in the U.S.

The map below illustrates the density of native palm species in the United States. As a side note, while palm trees can grow outside of this area, they will not be found in the wild outside of this zone. Source: bonap.org   Fourteen species of palms, belonging to nine genera, are native to the U.S.. Only one occurs in the West; the others are naturally distributed in the southeastern and southern States - from North Carolina through Florida and the Gulf Coast into Texas and as far inland as Arkansas and southeastern Oklahoma. Some of them cover extensive areas. The greatest number of species occurs in Florida. The total of 14 is a relatively large representation since the southern tip of Florida is the only essentially tropical portion of our country. In addition, 2 Old World palms, the coconut and the date, have become naturalized; that is, in many areas where they have escaped from cultivation, the climate and soil have proved so suitable for their growth that they appear to...