Tag Archives: earthquake

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.

A Century Later, The Heroes of the Baltic Fleet To Be Remembered in Messina and Reggio Calabria

Two cities destroyed by Nature just after the holy days of Christmas; the wailing of the living, lost inside or outside the rubble; the waters of the Strait and their ripples in a light still confusing the sea with the horizon, full of a million pieces of what they had crushed in three waves of tsunami: that was the nightmare to which the Russian Baltic Fleet anchored in the early morning of 29 December 1908.

About twenty four hours had passed since one of the most devastating earthquakes in history, obliterating the cities of Messina and Reggio Calabria (and beyond) in Southern Italy, and with them around 100,000 people: and the Battleship Cesarevič was the first sign of any rescue from the outside world.

In an era where television serves death regularly at dinner time, it is hard to realize what horror is hidden behind the disappearance of one hundred thousand people in an area as small as that of the Strait of Messina. It’s as if somebody had killed three persons a day, on average, every single day for the past century.

And so the intervention of the Baltic Fleet is truly remarkable, and still remembered with all those indefatigable cadets, appearing strong beyond all imagination to the local population, true angels and saviours for thousands.

Who knows how many people would not be alive today, if their grandpa or great-grandma had not been rescued by the Russians? Perhaps extracted from underneath a collapsed building, or even “just” provided with a warm blanket, a place to sleep and warm food to survive especially in the first days after the tragedy.

The intervention of the Baltic Fleet will be remembered alongside the earthquake commemoration in a few days’ time, in the night of 27/28 December 2008, when the cities of Messina and Reggio Calabria will await that terrible hour of 5:21AM: because the sacrifice of hundreds, and the death of tens of Russian sailors should not be forgotten in the maelstroms of history.

Don’t Stop Digging

After an earthquake, and after the quake (or perhaps, the quakes) in China this month, talks of ”too much time has passed for anybody to be still alive” chillingly keep coming back.

It is actually known since the Messina earthquake of 1908 if not longer, that humans can survive well beyond what we can imagine. Hope should never die, or at least for three weeks. Certainly not after just a handful of days.

Dig, dig, dig: nothing else makes sense, right now.