Tag Archives: Chile

Model Slaves A Common Feature At NASA

(Don’t miss out on the bonus atmospheric reference at the bottom of this blog)

Should computer modeling be banned from NASA premises? Recent grandiose public statements may suggest as much.

March 1, 2010: NASA.gov: “Chilean Quake May Have Shortened Earth Days

The Feb. 27 magnitude 8.8 earthquake in Chile may have shortened the length of each Earth day.

JPL research scientist Richard Gross computed how Earth’s rotation should have changed as a result of the Feb. 27 quake. Using a complex model, he and fellow scientists came up with a preliminary calculation that the quake should have shortened the length of an Earth day by about 1.26 microseconds (a microsecond is one millionth of a second).

Perhaps more impressive is how much the quake shifted Earth’s axis. Gross calculates the quake should have moved Earth’s figure axis (the axis about which Earth’s mass is balanced) by 2.7 milliarcseconds (about 8 centimeters, or 3 inches). Earth’s figure axis is not the same as its north-south axis; they are offset by about 10 meters (about 33 feet).

March 4, 2010: ASI (Italian Space Agency)’s Space Geodesy Centre in Matera, Italy – since 2004, the Official Primary Combination Centre for the International Laser Ranging Service (ILRS): “The earthquake in Chile and the polar axis: analysis from our centre in Matera

Using data from the International Laser Ranging Service, the global system which uses lasers to measure, with millimetre resolution, the distance between a network of stations on Earth and reflectors on satellites, the ASI Space Geodesy Centre in Matera[…]  calculated the residual motion of the pole in comparison with values from immediately before the earthquake. Preliminary results do not show significant disparities, i.e. greater than one millisecond of arc, equivalent to about three centimetres.

March 11, 2010: NASA.gov: “Did the Chilean Quake Shift Earth’s Axis?

On Feb. 27, 2010, the Chilean quake may have moved the figure axis as much in a matter of minutes as it normally moves in a whole year. It was a truly seismic shift—no pun intended. So far, however, it’s all calculation and speculation. “We haven’t actually measured the shift,” says Gross. “But I intend to give it a try.” The key is GPS.

[…] The stage is set for discovery. “Computing power is at an all-time high. Our models of tides, winds and ocean currents have never been better. And the orientation of the Chilean fault favors a stronger signal.” In a few months Gross hopes to have the answer. Stay tuned.

A dime to the first person that will make Dr Gross acquainted with ILRS!

ps Check out how doubt-free NASA’s outreach has been on the topic

Why did the earthquake in Chile shorten the day? As I explained previously in the chat, the earthquake in Chile caused the mass of the Earth to shift, which caused the figure axis (the axis about which the mass of the Earth is balanced) to change. This change in the mass of the Earth caused a changed in the rotation rate of the Earth, making it speed up slightly, thus shortening the day.

pps Finally, an atmospheric bonus…here’s how ASI explained their results being different from NASA’s

This evaluation differs from those obtained using theoretical models of the planet (such as the one produced by the Jet Propulsion Lab in Pasadena, California) which can estimate the extent of a shift on the basis of geophysical and seismological data. This is the type of calculation used in meteorological forecasts, which are based on data observed before a particular date and on theoretical models of how atmospheric phenomena develop.

And of course they are.

Ban Ki-Moon’s Remarks on Chilean Children

In “Alarming UN report on climate change too rosy, many say” (IHT, Nov 18) Elisabeth Rosenthal and James Kanter report that UN Secretary General Ban Ki-Moon has “described […] children in Chile having to wear protective clothing because an ozone hole was letting in so much ultraviolet radiation.

Is that actually happening in Chile?

I have not been able to find any evidence supporting such a strong statement.

(1) Pubmed through keywords “chile”, “ultraviolet” and “children” shows an article by Aranibar et al [Association between sunburn in children and ultraviolet radiation and ozone layer, during six summers (1996-2001) in Santiago, Chile (33,5 degrees S)] Rev Med Chil. 2003 Sep;131(9):1011-22.

I cannot find the original article, but the abstract seems to report that the behaviour of children 6-10 is at risk of sunburn (hardly world-shattering).

(2) From that article I was able to find more relevant stuff. There is one by Abarca JF, Casiccia CC., “Skin cancer and ultraviolet-B radiation under the Antarctic ozone hole: southern Chile, 1987-2000. Photodermatol Photoimmunol Photomed. 2002 Dec;18(6):294-302.

It reports that people of whiter skin may suffer in Punta Arenas due to repeated exposure, and increased rates of skin cancer may be occurring, and recommends further research.

(3) Another related article is by Abarca JF, Casiccia CC, Zamorano FD., “Increase in sunburns and photosensitivity disorders at the edge of the Antarctic ozone hole, southern Chile, 1986-2000”, J Am Acad Dermatol. 2002 Feb;46(2):193-9.

It indicates the worries but lists no actual skin cancer data.

(4) Then of course there is Molgó M et al, [Sun exposure behaviors and knowledge among Chileans] Rev Med Chil. 2005 Jun;133(6):662-6. Epub 2005 Jul 22. In Spanish.

It’s a survey and reports risky behaviours. Once again, no data on Skin Cancer.

(5) I then visited the website for CONAC, the Chilean ONG about Cancers. The pages of the National Network of Ultraviolet Medicine mention a prevalence of 10/100,000 among Chileans for skin cancer

(6) As a comparison, in England the prevalence among Europeans is 13/100,000

(7) “Environmental Journalist” Stephen Lehay writes a year ago that “Ailments Surge as Ozone Hole Widens” indicating that “Diagnoses of malignant melanoma, a deadly form of skin cancer, have doubled in recent years, leading Chilean health authorities to recommend avoiding direct exposure to the sun between 11:00am and 5:00pm, and especially to protect children”.

No sources and no absolute values are reported for this information.

(8) The same Lehay writes a couple of months ago “Skin Cancer Rising Despite New Ozone Deal to Cut CO2 Emissions” making a controversial connection betweeen skin cancer rates in the USA and a “crippled” ozone layer.

Being an environmental article (here in full) it can’t help predicting soaring numbers of cancer victims by 2060


In conclusion:

(a) Peer-reviewed work has not find much interest in Chilean children, or better yet in any Chilean skin cancer.

(b) At best, CONAC (the Chilean ONG on Cancer) is recommending protection in the middle of the day, but that is good advice the world over especially in summer, and nothing special about Chile.

Either children in South America are risking their lives as we speak among a global indifference, or the UN Secretary General has “sexed up” the truth.

One wonders.