Andrew Alden earned his geology degree at the University of New Hampshire and moved back to the Bay Area to work at the U.S. Geological Survey for six years. He has written on geology for About.com since its founding in 1997. In 2007, he started the Oakland Geology blog, which won recognition as "Best of the East Bay" from the East Bay Express in 2010. In writing about geology in the Bay Area and surroundings, he hopes to share some of the useful and pleasurable insights that geologists give us—not just facts about the deep past, but an attitude that might be called the deep present.
Andrew Alden's Latest Posts
Tsunamis are a worldwide menace with specific local threats. It pays to learn your local situation and keep the knowledge fresh in your community.
Large earthquakes are in our future. When one strikes, there are ways you can help scientists study the event using your phone.
New data from the ancient ice of a tropical glacier shows that lead in gasoline tainted the Earth with the toxic metal far more than any other source, past or present, human or natural.
Geologists are familiar with something most of us have never seen—spherules, or microscopic balls of natural glass that hide in sediments all over the world. A new study reports a previously unknown kind of spherule that’s forged during volcanic eruptions as lightning lashes roiling clouds of hot ash.
A long record of atmospheric observations has put an "official" stamp on the foundation of climate-change science: the greenhouse effect really works the way we've always said it does.
Scientists must play catch-up to industry as we figure out ways to use the deep underground without triggering earthquakes.
Our best climate models, combined with our best climate records, foresee at least a century of profound drought in the Midwest and Southwest.
The large asteroid Vesta has added flows of material rich in water to its bag of tricks. It's just one more way this small world acts like a proper planet.
For geologists, even with the advent of modern technology, there are instances when older methods are more effective; picks and shovels are sometimes the best complementary tools available for trenching studies.
A reassessment of historical data suggests that compared to previous estimates, the world's sea level rose more slowly during the 20th centuryand is rising faster now.
A new way of measuring soil erosion in the geologically recent past, before modern civilization, may help put sustainable agriculture on a firmer footing.
A new set of rock dates have pushed volcanism back into the debate over the extinction of the dinosaurs.
The just-released seismic resiliency plan for Los Angeles goes beyond just saving lives; it hopes to ensure that the nation's second-largest city will still work after a magnitude 7.8 earthquake.
Thanks to a meteorite collected in 1879, we have finally given a name to the most abundant mineral in Earth. Here's why it took so long to christen this stuff.
The cutting edge in earthquake research is mapping our most important faults in three-dimensional detail. A new paper finds some key hidden links in the Bay Area's fault system.
When a court convicted earthquake scientists of manslaughter, seismologists everywhere feared the worst for their own efforts at informing the public. After the convictions were overturned on appeal this week, experts, journalists and the general public can consider the wider lessons learned.
The iconic Tuolumne Meadows, in the high Sierra, is a geological puzzle. A newly published study traces the roots of the meadows to an incident deep in time and deep below the ground.
Oakland gains character as well as affordable housing from its stock of small and mid-sized apartment buildings. A retrofit plan is being prepared to strengthen this crucial part of the city's fabric against earthquake damage.
The familiar GPS system is being enlisted to help improve earthquake shaking alerts; an experimental system is now operating at the Berkeley Seismological Laboratory.