30 November 2011

Clustering of Large Earthquakes Explained by Random Variability?

Sumatra, 2004. Chile, 2010. Japan, 2011. Odds are these names and dates ring a bell. The scars are still too fresh and widespread for them to have slipped from memory. They identify, of course, the three largest recorded earthquakes that have occurred in the last 45 years — with magnitudes of 9.1, 8.8 and 9.0, respectively. Add in the 2005 magnitude 8.6 quake that also hit Sumatra, likely triggered by the 2004 event, and you’re talking about the four largest earthquakes in roughly the last half century all occurring within a few years of each other. It seems strange that they have been so bunched up, doesn’t it? 
An aerial view of Minato, Japan taken about a week after the
March 11, 2011 magnitude 9.0 earthquake and resulting tsunami that
devastated large swaths of the Japanese coast. (Credit: Lance Cpl.
Ethan Johnson, U.S. Marine Corps, Creative Commons Attribution
2.0 Generic)
In fact, there was a similar sequence of major earthquakes in the middle of the last century as well: Kamchatka, magnitude 9.0, 1952; Chile, magnitude 9.5, 1960 (the largest known earthquake); and Alaska, magnitude 9.2, 1964. No other 9.0+ events were recorded in the 20th century. Throw in a few more 8.5+ quakes in the same time frame, and you’ve got quite a cluster of destructive temblors occurring over just a decade and a half.

Contrast these turbulent stretches with the decades-long periods before 1950 and from about 1965 until 2004, when the planet was relatively calm, seismically speaking, and it certainly appears that these enormous earthquakes timed so close together are connected by more than coincidence, right? And if so, shouldn’t we be expecting more major quakes in the near future as one popular author suggested following the earthquake off the coast of Japan last spring?

21 November 2011

How the Webb Space Telescope got its groove ... er ... funding, back

 After several months of uncertainty, the future of NASA’s James Webb Space Telescope (JWST) appears to be secure, at least for another year. Lawmakers in both the House and Senate voted last Thursday to pass an appropriations bill (pdf) that, among its many other allocations, includes $530 million in funding for JWST for fiscal year 2012.

An artist's rendering of the James Webb Space Telescope
(image credit: NASA)
Since construction of the massive instrument — slated to succeed and surpass Hubble — began in 2008, it has been beset by delays and cost overruns that have earned it many critics. While NASA originally proposed a $1.6 billion price tag, that number has continued to climb and the most recent estimate is closer to $8.7 billion. Similarly, the launch date, originally set for 2011, has been pushed back several times and now is scheduled for 2018.

An independent review (pdf) released in late 2010 concluded that the project’s problems had been caused primarily by administrative failures and chronic underfunding from the beginning rather than technical issues. Whatever the cause, the House Subcommittee on Commerce, Justice, Science and Related Agencies — a part of the House Appropriations Committee — had had enough. In July, the subcommittee proposed cutting $1.6 billion from NASA’s overall budget compared to 2011, and explicitly called for the JWST project to be terminated in its FY2012 draft spending bill. This prompted a significant outcry from many (though not all) scientists who see JWST as imperative to achieving priority research goals. Then, in September, the Senate Commerce, Justice and Science Appropriations Subcommittee, headed by long-time Webb supporter Barbara Mikulski, D-Md., released its own FY2012 draft spending bill (pdf) in which JWST faired far better.

14 November 2011

Five Interesting Things I Heard About: Solar Energy

One of the great things about living in a university town like Madison, Wis. is that there is a never-ending supply of interesting talks to attend and scholars willing to give those talks. While the talks are rarely dull and I do my best to pay attention, I’ve found that much of the material presented often escapes me soon afterward. You know, you get to worrying about work or school or what’s on your grocery list (daily life, in other words) and you forget the interesting stem cell development, the surprising statistic about corn ethanol production, or the fascinating hypothesis about mantle hotspot dynamics that you just heard. It’s not easy retaining so much information, even when it is interesting, surprising and fascinating stuff.

(Image credit: (c) pixor, CC BY-NC-SA 2.0)
In the spirit of trying to preserve some of this awesome info that might otherwise be lost, I thought I’d mix things up with the blog here and introduce a new series of posts entitled “Five Interesting Things I Heard About: [blank].” This is a largely self-motivated exercise of course, but I hope I manage to keep it interesting for you, the reader, as well.

The first installment comes from a guest lecture by Sandy Klein, a professor of mechanical engineering and director of the Solar Energy Lab at the University of Wisconsin at Madison, as part of a course about energy resources. Klein spoke about the basics of energy use in the U.S., including solar, where solar technology is now and where it’s headed: