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uk.sci.weather (UK Weather) (uk.sci.weather) For the discussion of daily weather events, chiefly affecting the UK and adjacent parts of Europe, both past and predicted. The discussion is open to all, but contributions on a practical scientific level are encouraged. |
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#12
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![]() "John Hall" wrote in message ... In article , a writes: I heard some report saying the quake that caused the tsunami was so great it shifted the earths axis of rotation by an inch or something - is that true, and how on earth (lol) do you measure something like that on a planetary scale!? That was covered in a thread on here a week or so ago. It shouldn't be hard to find on Google. sorry, dont get here very often ![]() |
#13
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via sci.space.news
FOR IMMEDIATE RELEASE: 1/10/05 NOAA 2005-104 NOAA SCIENTISTS ABLE TO MEASURE TSUNAMI HEIGHT FROM SPACE After reviewing data from four Earth-orbiting radar satellites, NOAA scientists today announced they were able to measure the height of the devastating tsunami that erupted in the Indian Ocean. The ability to make depth surveys from space may lead to improvements in the models that forecast the hazardous effects of tsunamis. NOAA is an agency of the U.S. Department of Commerce. The height goes down over time as the wave spreads over the ocean and the energy is expended on shore. At 2 hours after the quake, it was 60 cm (about 2 feet) high. By 3 hours 15 minutes after the quake, that dropped to around 40 cm (about 16 inches) high. By 8 hours 50 minutes after the quake, the wave spread over most of the Indian Ocean and was quite small in most areas -- 5 to 10 cm (2 to 4 inches) -- about the limit of the satellite resolution. However, the wave was still large enough after all that elapsed time that it was still bouncing around in the Bay of Bengal still appears about 25 cm high (10 inches) as measured by the satellites. Several days after the Indian Ocean tsunami, scientists from NOAA's Laboratory for Satellite Altimetry in Silver Spring, Md., examined data from the four spacecraft -- the TOPEX/Poseidon and Jason, operated jointly by NASA and the French space agency, CNES; the European Space Agency's Envisat and the U.S. Navy's Geosat Follow-On. "By chance, these satellites were in the right place at the right time," said Walter H.F. Smith, a geophysicist at the NOAA LSA, which routinely monitors sea-level variations from space using radar measurements taken by several satellites. The measurements are used to make simple charts of unexplored ocean basins, and to forecast the intensification of hurricanes, the onset of an El Niño, and other weather and climate events. Upon further investigation of satellite data, NOAA researchers were able to detect the Indian Ocean tsunami in profiles of sea level along the satellites' flight paths by comparing the sea level seen on Dec. 26, 2004, with the sea level measurements the satellites picked up a few days, or weeks, earlier. Also, U.S. and French teams, working in parallel with data from the joint NASA/French Space Agency's Jason and TOPEX/Poseidon, independently confirmed the satellites' measurements of the height of the tsunami waves. "These observations are unique and of tremendous value for testing and improving tsunami computer models and developing future tsunami early warning systems," said Lee-Lueng Fu, of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Smith emphasized that LSA does not get the satellite data until several hours after a tsunami has developed -- too late to be used as a real-time forecast. "Right now, this technique is not a first line of defense in tsunami hazard monitoring and warnings, but it gives scientists a window to tsunami activity in the deep and in remote parts of an ocean basin, too far away from coastal tide gauges and other instruments that could detect it," Smith added. Smith said NOAA researchers proposed that the best application of satellite data to improve tsunami hazard forecasts would be a reconnaissance mapping of the ocean floor from space. "The detailed shape of the sea bed, all across the ocean basin, determines the focusing -- or diffusion -- of tsunami energy barreling toward the coast." At NOAA's Pacific Marine Environmental Laboratory in Seattle, scientists have developed a computer model, showing how the tsunami moved across the Indian Ocean. Combined with the data from LSA, the PMEL model showed the changing sea levels along the flight paths of the four satellites, which crossed the ocean basin after the earthquake. PMEL scientists apply the tsunami computer model to provide hazard assessments for communities at risk, and develop a real-time forecast system for NOAA's Tsunami Warning Centers. Vasily Titov, an oceanographer at PMEL, said the satellite observations would be used in ongoing research to improve the understanding of how tsunamis move across the ocean. The NOAA Satellite and Information Services is America's primary source of space-based oceanographic, meteorological and climate data. It operates the nation's environmental satellites, which are used for ocean and weather observation and forecasting, climate monitoring, and other environmental applications. Some of the oceanographic applications include sea-surface temperature for weather forecasting and sea-surface heights for prediction of El Niño and hurricane intensification. NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation's coastal and marine resources. Relevant Web Sites * NOAA http://www.noaa.gov * NOAA's Satellite and Information Services http://www.nesdis.noaa.gov * NOAA Laboratory for Satellite Altimetry http://ibis.grdl.noaa.gov/SAT/ * NOAA Satellites http://www.noaa.gov/satellites.html |
#14
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Scott Whitehead wrote:
Don't fall off your chairs laughing, everybody, but there is an article in today's (Tuesday) Sun which is blaming the weekend's gales and heavy rain on the tsunami! Astrophysicist Piers Corbyn believes the tsunami "could have an effect on the weather". He is quoted as saying: "The immediate effect is that it has put a lot more water on the land. This will evaporate more quickly and so make the atmosphere damper." It's a "big fear haunting weather scientists". The article is on P25 if anyone is chomping at the bit to buy a copy!! Why are people so closed minded? As soon as you dismiss something and close your mind to it you are limiting your potential. I truly believe we should all spend time thinking about other possibilities every day. According to NASA the tsunami has changed the day's duration, the north pole has shifted by centimeteres and the shape of the Earth has changed. If this wasn't reported by NASA but just mentioned on a radio show you would all be ridicluing the statement. Would you not? I don't believe the tsunami caused this weekends gales, but I am not ruling it out 100%, also I am not ridicluing it. Learning to respect other people points of views is a good lesson to learn, not easy but worth doing. Open you minds! Graham |
#15
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"Dave Ludlow" wrote in message
... On 10 Jan 2005 16:41:48 -0800, (Scott Whitehead) wrote: Don't fall off your chairs laughing, everybody, but there is an article in today's (Tuesday) Sun which is blaming the weekend's gales and heavy rain on the tsunami! Astrophysicist Piers Corbyn believes the tsunami "could have an effect on the weather". He is quoted as saying: "The immediate effect is that it has put a lot more water on the land. This will evaporate more quickly and so make the atmosphere damper." It's a "big fear haunting weather scientists". The article is on P25 if anyone is chomping at the bit to buy a copy!! He's not the only one in need of some education. A spokeswoman for the Energy Watchdog (whatever it's called) was interviewed about the Carlisle floods yesterday, on Sky News. She said: "I don't know if this heavy rain was caused by the tsunami, but..." I kid you not. This must be a candidate for Quote of the Year. -- Dave *wringing his hands in despair* The Sun, Sky News - enough said about them, the reporters and the organisation for which they work. What will it be next from them? Something like: "All the extra water dumped on this Country as a result of that damper atmosphere will in turn evaporate and be carried even further north into the Arctic, creating a damper atmoshere there and as a result a raging (even for that area) blizzard over Greenland causing the ice sheet to grow significantly in size, leading to a significant cooling of the Arctic and will then lead to 2005/06 being the coldest winter the Northern hemisphere has ever known"? I wouldn't put it past them. In the past, the average 5 yr old schoolchild has been shown to know more about the properties of water and ice crystals at different temperatures than some reporters working for that organisation! Furthermore, wasn't it the above Newspaper that carried a headline late last January that the cold spell we were all waiting for had been delayed because the cold air was taking longer than expected to get here from Canada? Just glad I don't contribute in any way with any of their products to their coffers. -- Pete Please take my dog out twice to e-mail --------------------------------------------------------------- The views expressed above are entirely those of the writer and do not represent the views, policy or understanding of any other person or official body. --------------------------------------------------------------- |
#16
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Mike Tullett wrote:
On Tue, 11 Jan 2005 10:37:17 -0000, a wrote in I heard some report saying the quake that caused the tsunami was so great it shifted the earths axis of rotation by an inch or something - is that true, and how on earth (lol) do you measure something like that on a planetary scale!? See http://science.nasa.gov/headlines/y2...htm?list962280 And quoting therefrom: "devastating megathrust earthquake" ... if the word 'megathrust' exists (and it does now I suppose) does it not mean 'a million thrusts' which in turn means that it is meaningless? "This continues the trend of earthquakes making Earth less oblate. Less oblate means more round." ... as an unqualified person, but a logical one, I would think they are looking at that backwards. The natural tendency of a spinning ball to become spherical might cause the plates to move with resulting earthquakes perhaps? "None of these changes have yet been measured--only calculated. But Chao and Gross hope ..." ... aye we all hope. I do not mind if I am incorrect. I would only mind if I do not know I am incorrect. -- Gianna Stefani www.buchan-meteo.org.uk |
#17
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"Mike Tullett" wrote See
snip http://science.nasa.gov/headlines/y2...htm?list962280 Thanks, Mike. I notice the tailpiece to this article says: "None of these changes have yet been measured--only calculated. But Chao and Gross hope to detect the changes when Earth rotation data from ground based and space-borne sensors are reviewed". Apart from the uncertainty this implies, I'm sure that other natural forces are doing similar things - some maybe more, some less - without attracting any of this attention. Which (I'm afraid), in my book, makes this sort of hype a total non-event. - Tom. |
#18
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"He who knows not and knows not he knows not, he is a fool - shun him;
"He who knows not and knows he knows not, he is a child - teach him; "He who knows and knows not he knows, he is asleep - wake him; "He who knows and knows he knows, he is a wise man - hear him!" I wonder which category Piers Corbyn fits?? Anne |
#19
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Felly sgrifennodd Tom Bennett :
"Mike Tullett" wrote See snip http://science.nasa.gov/headlines/y2...htm?list962280 Thanks, Mike. I notice the tailpiece to this article says: "None of these changes have yet been measured--only calculated. But Chao and Gross hope to detect the changes when Earth rotation data from ground based and space-borne sensors are reviewed". But something remarkable seemed to happen around 26/12 to the UT1-UTC values according to http://maia.usno.navy.mil/search/search.html. Try putting in dates from around 20/12 to today and see what you get. Or was this just coincidence? (UT1 is solar time, UTC is atomic clock time) Adrian -- Adrian Shaw ais@ Adran Cyfrifiadureg, Prifysgol Cymru, aber. Aberystwyth, Ceredigion, Cymru ac. http://users.aber.ac.uk/ais uk |
#20
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![]() "Anne Burgess" wrote in message ... "He who knows not and knows not he knows not, he is a fool - shun him; "He who knows not and knows he knows not, he is a child - teach him; "He who knows and knows not he knows, he is asleep - wake him; "He who knows and knows he knows, he is a wise man - hear him!" Anne, it seems to me there are one or two categories missing ... :-) For instance, "he who knows and knows he knows, but seeks to mislead by pretending to know something else ..." pe |
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