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The Cajon Pass - the narrow valleys that connect the Los Angeles Basin to the Mojave Desert, in-between the San Gabriel and San Bernardino Mountains. The jog in the road is literally the San Andreas fault.
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“Serengeti National Park is one of the most famous wildlife areas in Africa and is synonymous with wildlife and classic African scenery. Established in 1951, the Serengeti is Tanzania’s oldest park and a Unesco World Heritage Site. It is home to the spectacular wildebeest and zebra migration and offers some of the best wildlife viewings in Africa.”
The Externsteine
The natural sandstone outcrop of Externsteine is a rare sight in the German Teutoburger forest, which is largely devoid of rocks. Throughout history this remarkable rock formation has been subject to debate, mostly about its possible function as a ‘Germanic’ cult site.
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Why seismic design is important, a three decade remembrance.
These images are of the formerly two-deck Cypress Structure on the route of Interstate 880, the Nimitz Freeway in Oakland, California after the 1989 Loma Prieta Earthquake. When we arrived in the SF Bay Area in the early 1960s, the highway was known as State Route 17 and there was some amount of scandal over alleged shortcuts taken in the construction. Not enough rebar, not enough portland cement in the concrete and more. It didn’t help that the pilings were set into bay mud that wasn’t particularly stable. Even with normal traffic, the structure shook and vibrated badly and I hated driving on it.
So with just 15 seconds of shaking, down it came.
A Pictish seastack
Once upon a time, Dunnicaer in Northern Scotland was a small cliffy peninsula attached to the mainland and a Pictish sea fort mounted above its cliffs. Nowadays Dunnicaer is a sea stack, a block of erosion resistant rock that is isolated from the mainland by the sea.
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Classic map
The Yellowstone area was declared America’s first National Park in 1872. For decades, no one really knew what a national park meant other than it was something of an interesting area – the U.S. Army even occupied the territory for years to provide some amount of protection for its resources against outsiders who wanted to make money off of the park’s features.
Even though no one really knew what a national park was, within 6 years of the park being declared, geologists had a basic idea of what was going on there, as shown by this 1878 vintage geologic map.
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The New Madrid Seismic Zone
About once a year, residents of the counties at the border between Kentucky, Tennessee, Missouri, and Arkansas will feel the ground roll beneath their feet. This image maps out the location of earthquakes in this area over a 30-year period and clearly illustrates a major feature: the New Madrid Seismic Zone. This zone produces about 1 quake that can be felt per year in addition to many small earthquakes…and has historically produced really big ones.
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No way I could find a 1943 vintage, now-digitized video titled “Brazilian Quartz Goes to War” and not share it on #MineralMonday.
