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Prof Van der Hoeven said: "The extraordinary thing about this meteor strike is that it appeared to do so little damage. Unlike the dinosaur strike there is no telltale layer of dust that demonstrates the history of the event. It may have damaged things and wiped out species but there is no sign of it."

One thing that did happen at exactly the same time was the reversing of the Earth's magnetic field. There is no other explanation as to why this took place and Prof Van der Hoeven believes it was caused by the impact.

Does this mean we're safe a a few more years

"Although fast by geological standards, reversals are by no means quick on the human time scale. They take roughly 5,000 years, with estimates ranging from 1,000 years and 8,000 years.

Both the total magnetic field and its dipole component decrease substantially during a reversal to values that range from 10% to 25% of the pre-reversal strength.

A reversal does not proceed in a uniform fashion. Large and rapid changes in direction and intensity are punctuated by periods of little change. During some transitions the field starts to change but then rebounds to near normal before the reversal finally goes to completion.

The scarcity and ambiguity of observations have led to two competing theories explaining how the magnetic field pattern changes, and how the magnetic poles behave during a reversal. According to one theory, the magnetic field remains predominantly dipolar during a reversal, and the poles migrate along preferred paths from one hemisphere to the other. According to another theory, the dipole portion of the magnetic field shrinks to zero but then regrows with opposite polarity. During the interval during which there is no dipole, the non-dipole part of the field persists, and the magnetic poles would not migrate in a systematic fashion."

Incidentally, University of Arizona is where E. Philip Krider works in the Department of Atmospheric Sciences - he basically spearheaded the development of lightning detection systems. Coincidence? Probably not.

Or you could do like our neighbors up north and pick up a block heater

Check out Environment Canada's numbers. The VW TDI's blow almost everything away with their efficiency. There is quite a difference between them and the Honda Insight, but their performance is much much better too. I've been thinking of selling my Passat (1.8L Turbo) and getting Golf or Jetta TDI mostly because of the economy, and then also because hauling around a huge car that's normally empty is just stupid.

I'm glad the Canadian goverment introduced legislation a couple of years back that will see cleaner diesel soon. Anybody know if the US will be seeing the same standards imposed? Also, anybody know if it will up to European standards? If so, then perhaps we will start seeing the really diesels they get but we can't have.

Maybe 10 years ago GPS wasn't good enough. However, it is good enough for land titles in British Columbia (not very many survey monuments to tie into for minesites in the middle of nowhere). I don't know if I would want to do building construction layout (millimetre accuracy) using GPS, but if GPS is fine for land titles, it should be OK for most purposes. The Geodetic Survey Division of Natural Resources Canada has some more info on the different GPS methods. Check out the final part on Carrier Positioning accuracy - sub centimetre (10mm) is acheivable.

Giving a value on the Richter scale is not really meaningfull. You can have a 7 earthquake doing almost no damage if it happens far below earth surface and big damage with a 4 one near the surface in a low developped country.

It all depends on where the earthquake takes place.

You should use an estimate on the Mercalli scale. I find it more relevant.

Richter scale is all about energy released, Mercalli scale is all about damage/lost of lives which really is what matters.

The download instruction page states "The full mosaic image file is in an ECW format. You can view this product with a free viewer called ER Viewer...

ECW is Enhanced Compressed Wavelet. developed by ERMapper. The image was compressed using ECW because it was pieced together using ERMapper. 3.2 GB fits nicely on a DVD.

Has anyone else downloaded the image? How long did it take?

I think the source data is indeed MrSid. Apparently the source data is freely available on the internet as well. For example, compare the area northwest of the Hudson Bay (just above the center of the image showing entire Canada ) to this page. (You need to accept a certificate.) Note the two reddish/brownish areas. Coincident? Nah. :) Also the clouds, light reflection and ice coverage is similar to the ESAD images. BTW, Almost the entire world is available at the ESAD site, with 28.5 m resolution.

Link.

After looking, I don't even see the bold text you copied from the article..

Link to the download page: http://www.pfc.cfs.nrcan.gc.ca/eosd/resources/mosa ic_e.html

Anyone have a torrent yet?

Neat, I can actually see the University of Alberta where I work.

no really, I can

As I recall from the Nova program, a field reversal was essentially caught in the act by a single layer of lava. The interior of the lava flow had frozen in it a magnetic field 6 degrees different from the field frozen in the top and bottom of the flow, which cool faster due to contact with the atmosphere and the ground. This happened in a short period of time (days or weeks?). So saying "at that rate of decline" is pointless, as the rate of change would probably increase during a reversal. To illustrate, I'd like to point out that the north magnetic pole has been migrating further north at an accelerating pace. Although the link's text claims the acceleration occurred around 1970, their map shows it started sometime between 1904 and 1948, with perhaps a brief deceleration in the '60s.

And the sun is becoming more active at the same time. Things could get quite interesting on our little planet.

Just take a pen and swap 'N' with 'S' and 'S' with 'N'.

Just a bit of advice: You may also want to relabel the East and West indicators or you will find yourself being very confused. Granted, in the case of Magnetic Reversal, you may end up more than just confused.

I understand the joke but the fact is while USA represents a very small percentage of the world population, it is responsible for 20% of total CO2 emission in the world (pdf). CO2 is well known to contribute to global warming and some countries engaged themselfs to reduce their CO2 emission. But not the USA... This is going offtopic and it gives a negative point of view of US. Mod me down.

If I had gone and said the north american power grid should be replaced at the wake of the outages [ . . . ], I would have been accused of countless acts of civil disobediance.

My first question is what is wrong with Slashdot? I mean someone saw fit to give the parent coward "Insightful" for what she or he wrote? Someone wind the clock back before 2000 when Slashdot wasn't frequented by Microsoft apologists.

I'm not sure what makes you think your exercising your 1st Amendment right to speak freely (assuming you're a US citizen) would be branded civil disobedince, but in case you're really worried (and not just ranting) know you're in good comapny: first, the outage of August 2003 has produced a US-Canadain task force to investigate problems with the aging power grid. In fact, the power grid is so important that it is the subject of dozens of assessments conducted by North American Electric Reliabilty Council. Let's just say that NERC is not sanguine about the reliability of the North-American power grid. The problem is so widespread that even US lawmakers anticipate a massive political dispute.

Regarding your comparison of the power grid to the Internet, network events such as MSBlaster and Sobig.F highlight the fragility of an information network built of insecure nodes. At present, the overwelming majority of the nodes of the Internet are powered by Microsoft software. For better or for worse, "press releases and open letters right at the wake [sic] of major worms" draw attention to the real effects of maintaining so insecure an information network. MSBlaster and Sobig.F are not theories but facts and so prove the unreliability of an Internet composed mainly of Microsoft-powered nodes. The timely discussion of network events such as MSBlaster, Mimda, Code Red, Sobig.X, etc. in the press should, in my opinion, be an obligation of network adminstrators.

Given your post, you'd probably have us ignore the problem in the hopes that the next worm/virus/trojan does not damage our shared information network even more spectacularly. Thanks, but I would rather disseminate information and share data about such network events rather than stop my eyes, ears, and mouth with sand.

Ever heard about the Northern Appalachian Seismic Zone?

It's just not as densely populated as California.

The Pacific Geoscience Center in Sidney, B.C. has been working with Washington state for several years in running the Western Canada Deformation Array - the same idea as the one in the UK. You can read about it here: http://www.pgc.nrcan.gc.ca/geodyn/wcda/wcda_ov.htm

FWIW, they've been doing this sort of thing in western Canada since 1991.

www.pgc.nrcan.gc.ca/geodyn/docs/wcda_bc/content.ht m

My first real programming job was at the Pacific Geoscience center (a decade ago), maintining the unix programs and scripts that downloaded seismic data from these remote GPS stations.

You say a cross section of : 100m x 100m

To me, that gives : 100m x 100m x 40 000 000m
Or 400 000 000 000 m3 copper.

Copper is 8.96 gr/cm3
Or, 8960 kg/m3

That gives you 3.584x10^15 Kg of Copper.

Acoording to :
Internation copper study group
, the world copper production is about 15000000 Kg/yr.

That gives us the final number of 238 933 333 years to extract the needed copper, assuming there is enough on earth.

I don't think this is possible.

Or you could try this site or this one to get the current declination.

The pole does not move in more traditional manets, but the earyth's liquid core might provide an answer.

It has been drifting nothward for decades.

More info at Canada's GSC site.

You DO realize that there is a SIGNIFICANT different between a SAPLING and a 100 YEAR OLD tree right?

Yes, saplings absorb more carbon dioxide than 100-year-old trees. I found this reference with Google to support that fact. See the third paragraph.

World view my ass, no trees in MY area means that _I_ can't breath.

I suppose that's why people regularly suffocate in the Sahara and Antarctica.

And quite frankly I don't GIVE A FUCK about some corporate 'sponsered' (read: EPA made them do it and/or they are making a profit out of it in the long run) program to replant trees. [Emphasis mine.]

Eh? So replanting trees is only good if the entity doing the replanting does not benefit? How does that work?

It's not the Seattle earthquake, it's the Olympia Earthquake :) They were looking for the one broken window in Seattle when Olympia had real damage. Bleh, get it right =P

That URL shouldn't have a space. Try http://www.ccrs.nrcan.gc.ca/ccrs/eduref/sradar/cha p3/c3p7_g2e.html.