Wikipedia:Reference desk/Archives/Science/2011 March 12

= March 12 =

how does a vacant space,hole( in electronis) have a mass?
in electronics mass of hole is considered. Hole is a vacant space created when electron is migrated to conduction band from the valance band. how can this free space have a mass? —Preceding unsigned comment added by 117.197.192.72 (talk) 01:24, 12 March 2011 (UTC)


 * It is not a real mass. It is an effective mass which basically mean that the hole moves around displaying a behavior which can be interpreted as if it was a particle with mass. Think about it. The hole moves about by having electrons jump from neighbor regions and filling the hole and living a vacancy behind. This motion is not instantaneous and respond to external forces (such as an external electric field) in such a way that we can interpret the whole thing as if a particle with positive charge and some non-zero mass was there. That's the hole. Dauto (talk) 02:19, 12 March 2011 (UTC)

Beyaz and Natazia
Where is the page for Beyaz so short at the moment? At the same time where is the page on Natazia as well? Basically, I would like to learn more about these birth control options. — Preceding unsigned comment added by Mybodymyself (talk • contribs) 03:57, 12 March 2011 (UTC)


 * WP does not have information on everything - yet. The article on Beyaz is short because no-one, including you, has added more information to it. The article on Natazia does not exist for very similar reasons. If you put 'Natazia' into google you will receive about 84,000 hits, some of these contain excellent information about Natazia. Richard Avery (talk) 08:23, 12 March 2011 (UTC)

Why is blood typing routine in Mexico, but not in the United States?
Question: Why is blood typing routine in Mexico, but not in the United States (outside of the contexts of blood-donation or surgery)?

Context: I'm in my mid 30s, was raised in the United States, now living in Mexico. I've never donated blood (shame on me!) or had surgery (knock on wood). Therefore I've never had any occasion to have ABO or Rh(D) blood-typing done. Neither I nor my parents know my blood type. (Father is A, mother is B, so I gather I could be anything, depending on their relative zygosity; no, I'm not asking you to determine paternity!).

It seems I'm not that unusual for someone from the USA; according to this website, 60% of Americans don't know (warning: this site also advocates the blood-type personality/diet quackery). More anecdotal confirmation: 1402 people on a US website professing blood-type ignorance.

Arriving in Mexico City, it appears that everybody here knows their blood type. It is requested on the driver license application, as well a myriad other government documents; it appears on taxi-driver medallions posted in every (legal) taxicab's rear passenger-side window. If the subject comes up, without fail every Chilango is incredulous that I don't know what to them is as basic a piece of personal information as one's birthdate or second (maternal) family name (whoops, I fail there, too!).

One Mexican friend has gone so far as to call my mother negligent and my doctor an idiot. "You need to know in case you're in an accident and need a blood transfusion!", she says. I reply, "My US doctor told me, 'You only get tested at the moment it becomes necessary, in the ER or blood donation van'." "But there's no time in an emergency! You could die while they're testing you!" Cue hysterical screaming.

More anecdotes: One of the poorest municipal governments in Mexico offers free blood-typing analysis

A Mexico State legislator proclaims obligatory blood type testing to be an unnecessary and irrelevant requisite for registering schoolchildren, implying that the practice is currently standard.

So what accounts for this difference? I accept my facts are all very anecdotal (perhaps there's a MEDLINE article somewhere beyond my search-fu), but what, if anything, could this say about respective medical practices/bureaucratic zeal of each society? Or other countries? Sorry for being long-winded!

--189.227.64.126 (talk) 04:03, 12 March 2011 (UTC) Gringo seudoanónimo


 * Knowing your blood type is useful for you and, really, only you. If you don't want to take the time to get a test (free from many places), then it is all on you. Once you decide to try and have children, then your blood type is important for the child also because there are possible complications based on the compatibility of the mother's and father's blood type. Chances are the mother's doctor will have both the mother and father checked. When my wife was first pregnant, her doctor had by blood type checked even though I already knew what it was - just to be sure. Beyond that, anything that may happen in which your blood type is important to others will include a blood type check. -- k a i n a w &trade; 04:20, 12 March 2011 (UTC)


 * I should have answered about the need for blood transfusion. It is safe to use O- blood while your blood type is checked (which takes minutes in an emergency, but 20-30 minutes under normal circumstances). By the time you finish some O- blood, your blood type will be known and you will likely be given your specific blood type. If, for some reason, there is no O- blood, O+ is usually safe to start with (with very rare complications). From what I've seen, O+ is usually in higher stock levels than O-, but I don't think that is because there is simply more O+ blood donated. I think it is because O- is used more. But, I never checked donation/usage statistics on that. I spend my time at the Red Cross doing experiments on how donating blood affects hypertension, diabetes, and hypercholesterolemia. I've only been surprised once: donating blood increases blood pressure for a few hours. Then, it is lowered for a couple days. I assumed it would be lowered for a few hours and then return to normal. But, it is late and I'm drifting quickly off topic. -- k a i n a w &trade; 04:27, 12 March 2011 (UTC)


 * In an emergency, Rh-negative type O blood can be transfused about as safely as type-matched blood that has not been cross-matched. Thus, it's arguably more efficient to maintain a stock of type O blood than it is to depend on typing everyone and assuming that the blood type document they carry is accurate (many people carry identification that belongs to someone else, for a variety of reasons, and might not be in condition to explain during an emergency).  As our Rh article I just linked points out, Rh negativity is much less common than Rh positivity, hence O- donors are significantly less common than O+ donors. -- Scray (talk) 04:42, 12 March 2011 (UTC)


 * In addition to the above, there is also a risk of mistakes, either a mistake in transferring data from the test to the ID-card or whatever, or because the ID-card belongs to a different person. The consequences of giving a transfusion with the wrong blood type can be disastrous, but there's usually no serious consequence if you take the time to check the blood type and give O-blood or other fluids in the meantime. Also, blood typing everybody will take resources that might be better used elsewhere. Source: Opinion from the Swedish Riksdag's comittee on social services Committee on Health and Welfare (Swedish).Sjö (talk) 10:53, 12 March 2011 (UTC)


 * I heard from someone at the ASBBC that the US military routinely retypes soldiers before sending them overseas because so many of the dogtags they get in basic end up being wrong. Other than the possibility for errors, you also have to find the card/ask the person/etc... in order to find the blood type, and honestly that might take longer than just a stat ABO type.  I'd guess that the difference between the US and Mexico is probably that the US has a much better blood bank infrastructure and at least a couple of units of type O blood are routinely available at any hospital (most hospitals I've seen have two or four units reserved precisely for this purpose).  Either that or living in Mexico is more dangerous and you're far more likely to need a transfusion...  SDY (talk) 12:46, 12 March 2011 (UTC)

Thanks for your responses. Paraphrasing somewhat polemically:
 * Kainaw: Blood typing is useful to individuals, but not to a society at-large. Implication: the US has made a rational choice, and Mexico has not, for some unexplained reason.
 * Scray: A blood bank infrastructure which maintains a stock of O+ O- blood is arguably more efficient. Implication: The US has this stock, Mexico does not and therefore inefficiently relies on individuals to carry accurate records. (BTW, most Mexicans are type O)
 * Sjö: Resources are more efficiently spent testing at the moment of need rather than beforehand. Implication: Mexico wastes its resources. Why?
 * SDY: The US has a better blood bank infrastructure than Mexico. Implication: Consequently, the individual burden to track blood type is eliminated. I'll ignore the joke about Mexico being more dangerous to live in... though its 2000 traffic accident death rate was 168% greater than the US (and 714% greater than Sweden's!)

The unspoken judgment in all of your responses is that Mexico has backward medical practices compared to the US, ie. economic factors rather than cultural explain the difference. Let me tell you that this view is not generally well received here in Mexico, and would likely be termed mamón, or "stuck up." The woman I mentioned above countered that Mexico, being a country with strong indigenous roots, has a longstanding pro-active, self-medicating tradition, where one must literally bring one's own medical records to each doctor visit. The US, by contrast, being an immigrant society, has discarded whatever traditional health participatory patterns and instead defers to its medical system to know what's best. Which is better might depend on one's values (or you could measure by life-expectancy, incidence of diabetes, etc.)

So, returning to the question; if it's just a question of economic development, aren't there counter-examples of wealthy/highly-developed societies where every person is expected to know one's blood type? Japan comes to mind, (I only know about it from reading about the popular belief in blood-to-personality typology, which Mexico incidentally does not share). --189.227.64.126 (talk) 04:33, 13 March 2011 (UTC) Gringo seudoanónimo


 * Every nation/culture has its superstitions. I don't think anyone who replied in this thread judged Mexico as less rational "on average" than, say, the U.S., just as less rational on this one particular point. If you want to talk about ways in which the U.S. wastes its resources, well, don't get me started. -- BenRG (talk) 08:57, 13 March 2011 (UTC)


 * IP189.227...'s summary of my comment is inaccurate though I do agree with their self-characterization of that summary as "somewhat polemical" . I did not suggest a stock of "O+ blood" (I specifically suggested O-). More importantly, each government must make their own decisions regarding how best to manage emergency supplies.  I simply stated that it is "arguably" more efficient to transfuse O- blood when transfusion cannot wait, and type & crossmatch in the meantime.  -- Scray (talk) 13:49, 13 March 2011 (UTC)


 * Corrected my arguable argumentative summary. Thank you, Scray. 189.227.64.126 (talk) 14:54, 13 March 2011 (UTC)


 * I agree that it's somewhat polemical, though maybe not wholly inaccurate. GSWs and MVAs aside, I'm actually looking at medical records in the Dominican Republic right now, and "self-medicating tradition" has left me a little... nonplussed.  People taking cipro for toothaches makes me want to modify the appearance of the nearest wall with my forehead.  SDY (talk) 15:45, 13 March 2011 (UTC)


 * There is plenty of self-medicating tradition in the United States also. I work in hypertension, diabetes, and hypercholesterolemia research. It is amazing how people who freely blow thousands of dollars every year on beer, cigarettes, and lottery tickets will penny-pinch over a $10/month medication bill. Further, there are cultural superstitions that border on insanity (in my opinion, they step clearly over the line). For example, there is a black culture superstition that hypertension is not real. It doesn't exist. It is a white supremacist trick to get black men to take hypertension medication that actually makes them sterile. So, black men (who are known to be at the highest risk for hypertension) tend to avoid hypertension medication out of fear that it will make them sterile. You cannot reason with self-medicating traditions because you cannot reason a person out of an opinion that he or she reached without reason. You just have to hope they don't pass it on their children. -- k a i n a w &trade; 18:17, 13 March 2011 (UTC)
 * I was with you, more or less, until you said "without reason". Are you unaware of reasons, based on documented history, why black men might believe that white Americans want them sterile?  For any that would accuse of digression, I am speaking scientifically here - this is relevant to self-medicating traditions, etc etc...  -- Scray (talk) 04:12, 14 March 2011 (UTC)


 * I was paraphrasing a popular quote: "You cannot reason someone out of something they were not reasoned into." It was one of Mark Twain's common quotes, though it is doubtful it is one of his original ones. -- k a i n a w &trade; 05:44, 15 March 2011 (UTC)

Tokyo's earthquake
2011 Sendai earthquake and tsunami: Most news sources claim that this earthquake is the biggest one ever recorded in Japan's modern history. However, Tokyo only experienced a seismic scale 5+ quake this time (thanks to the distance). This is big but not as big as the city-devastating quake the scientists warned about. So far most damages were caused by tsunami rather than the quake. Much of the city survived the quakes.


 * http://www.jma.go.jp/jp/quake/20110311145349391-111446.html
 * http://www.jma.go.jp/jp/quake/20110311150154391-111446.html
 * 東京都　　震度５強　東京千代田区大手町　東京江東区東陽 ...
 * Tokyo Metropolitan area, seismic scale 5+: Chiyoda Ward, Koto Ward, ...

Does it mean that this earthquake is still not the big one feared by the scientists? -- Toytoy (talk) 04:20, 12 March 2011 (UTC)

The big earthquake that was to destroy Tokyo aka the next Kanto Quake was due in 1995. 139.130.57.34 (talk) 04:36, 12 March 2011 (UTC)


 * I think this was the big one feared by scientists. It may not have been directly on-target, but an 8.9 earthquake sure does release a lot of energy. I think it will be a while before the next big one. --  T H F S W  (T · C · E) 05:19, 12 March 2011 (UTC)

I noticed that very few buildings in Tokyo collapsed because of the earthquake. Much of the subway system remains undamaged. The tsunami caused much more damage than earthquake. Japan's buildings survived the seismic scale 5+ quake. Since there are many more faults even closer to Tokyo may cause earthquakes, I doubt that the next big one is still waiting to happen. However, this disaster reminds us the seriousness of tsunamis. They are probably even worse than earthquakes.

This earthquake is MUCH larger than the Great Hanshin earthquake of 1995. However, since the Hanshin earthquake's epicenter was almost under the cities, many highly-developed metropolitan areas experienced seismic scale 6 to 7 rocking and shaking. Buildings collapsed. People were killed or rendered homeless. This time Tokyo's citizens suffer much less. On the other hand, people living in some coastal areas were wiped out completely because of the killing tsunami. -- Toytoy (talk) 08:11, 12 March 2011 (UTC)


 * The rupture area of the Sendai earthquake does not overlap with the estimated rupture area for the 1923 Great Kantō earthquake, so it's unlikely to have changed the risk for a re-run of that event, it might even trigger it, like the 2005 Sumatra earthquake, which followed close on heels of the 2004 Indian Ocean earthquake, rupturing an adjacent area of the Sunda megathrust. Mikenorton (talk) 12:57, 12 March 2011 (UTC)


 * The Sendai earthquake may have been close to the maximum strength for a Japanese quake but was certainly not the worst-case scenario. Such a quake would be a magnitude 9+ tremblor occurring near the Tokyo Bay region. Seismologists have not ruled out the possibility of M7+ aftershocks occurring very close to Tokyo Metropolitan Area. ~ A H  1 (TCU) 02:01, 13 March 2011 (UTC)

India a super power?
I AM A STUDENT FROM GOA,INDIA. I AM A SCIENCE STUDENT OF 2011 BATCH. I THINK INDIA HAS A MULTIDIMENSIONAL MILITARY FORCE TO SECURE ITS TERRITORY AND ENOUGH MILITARY STRENGTH TO COMBAT ANY A THREAT. — Preceding unsigned comment added by K55WI4DFG (talk • contribs) 09:20, 12 March 2011 (UTC)

Comment by Myles325a deleted per talk WikiDao    &#9775;  12:35, 15 March 2011 (UTC)


 * How is this a science question? SDY (talk) 12:47, 12 March 2011 (UTC)
 * How is this a question? --41.132.13.74 (talk) 18:08, 12 March 2011 (UTC)


 * I think India needs to test more powerful thermonuclear weapons before such a claim can be made. Count Iblis (talk) 15:14, 12 March 2011 (UTC)
 * That seems like a rather silly and arbitrary definition. 200 kilotons not good enough for you? Is it going to make you treat them differently than if they had 1 Mt? From a strategic standpoint, what matters less is the size of the boom (even 1kt is enough to be "unacceptable" if it goes off over a city), but where you can put it (if you can't deliver the thing, then it isn't much of a threat). --Mr.98 (talk) 16:21, 12 March 2011 (UTC)


 * My understanding is that many definitions of true "superpowers" are the ability to project force globally. Both the USA and USSR could have, essentially, put "men on the ground" on any continent. India cannot reasonably do this to my understanding. They do note even have secondary strike capability outside of the subcontinent. Securing your own territory just makes you a power — not a "super"-power. --Mr.98 (talk) 16:21, 12 March 2011 (UTC)


 * We have an article that discusses the possibility of India becoming a superpower. It doesn't seem particularly likely in the immediate future. Matt Deres (talk) 20:01, 12 March 2011 (UTC)


 * See veto power and regional power. ~ A H  1 (TCU) 01:55, 13 March 2011 (UTC)

F.A.G.E?
I HAD SEEN MY DOCTOR'S QUALIFICATION. IT WAS WRITTEN F.A.G.E. I HAD SEARCHED IN THE WEB SEARCH ENGINES AND COULD NOT GET THE ANSWER. COULD SOMEONE HELP ME OUT WHAT DOES F.A.G.E. STAND FORRaavi4321 (talk) 11:12, 12 March 2011 (UTC)
 * Possibly Fellow of Academy of General Education as offered by Manipal University. I can't identify if this is an actual qualification or a membership though. Nanonic (talk) 14:27, 12 March 2011 (UTC)
 * Fake Acronym to Gain Employment? Clarityfiend (talk) 20:26, 12 March 2011 (UTC)
 * "Fellow of [Professional Body]" is usually both a qualification and a membership. --Tango (talk) 20:21, 14 March 2011 (UTC)

Potentiometric Titration
Hello. Will I get a normal titration curve if I titrate, with a potentiometer, KIO3 in acidic solution against ascorbic acid mixed with starch indicator and KI? Thanks in advance. --Mayfare (talk) 17:26, 12 March 2011 (UTC)
 * See the Wikipedia articles Titration and Titration curve. Since a titration is a method of quantitative chemical analysis you will have to do the experiment to see the result. Cuddlyable3 (talk) 20:53, 13 March 2011 (UTC)

How did mid-twentieth-century fixists explain the dovetailing opposite coasts of the Atlantic Ocean?
How did recent "fixists" (opponents of the theory of continental drift, including Harold Jeffreys and others) explain the dove-tailing outlines of South America's east coast and Africa's west coast? 82.31.133.165 (talk) 20:32, 12 March 2011 (UTC)


 * Just coincidence, they could argue. After all, they aren't an exact fit, due to erosion and changing water levels.  Then they would point to all the adjacent continents that don't seem to match very well, such as the lack of an Italy-shaped indentation in North Africa.  StuRat (talk) 21:36, 12 March 2011 (UTC)


 * Unless you happen to have been a mid-20th century "fixist", your opinion about it doesn't matter to anyone other than you. Matt Deres (talk) 04:57, 13 March 2011 (UTC)


 * I don't agree. Studying the reaction of scientists who deny a new science has direct application today, such as those (few) scientist who seem to deny the existence of global warming (usually those with a big grant from somebody who wants them to say that). StuRat (talk) 08:54, 13 March 2011 (UTC)


 * What has that got to do with anything? The comment was directed at you, not the questioner. The OP wants to know what certain people thought/said/wrote about a particular topic. They're not interested in what StuRat would have said if he'd been there. Matt Deres (talk) 14:00, 13 March 2011 (UTC)


 * We have a history section in the continental drift article, and an entire article Timeline of the development of tectonophysics. From that article, I found this history book online, Scientific controversies... (by Arthur Caplan, 1987), with an entire chapter on the continental drift debate, and an entire sub-chapter entitled "The fixists' response to Wegener's drift theory" which should give you a pretty solid footing.  You could then pursue the original papers published by the involved parties.  Caplan lists several specific opponents of the modern theory of plate tectonics and continental drift.  Nimur (talk) 22:48, 12 March 2011 (UTC)

Limestone flakes changing color
I just noticed a limestone block that has pieces coming off in lighter colors. How/why do the pieces change color? They're definitely part of the original block: the contours of the pieces conform precisely to the contours of the section of the block on which they're sitting, and you can see that the piece in the top left gradually changes; it's only partly detached from the block. Moreover, how do the pieces come off? They've obviously not been moved or broken off by human action; is it simply the result of winter weather? Note that I've uploaded a more comprehensive image. Nyttend (talk) 21:30, 12 March 2011 (UTC)


 * The usual method is that water gets between the layers, freezes, expands, and breaks the layer off a bit further with each cycle. As for the color, water may be the culprit there, too, if the broken off pieces are able to dry out due to increased surface area and temperature (they would be air temperature, while the attached pieces would be closer to the ground temperature).  You might want to wet them down and see if they then look the same. StuRat (talk) 21:35, 12 March 2011 (UTC)


 * Yep, classic spalling / exfoliation. I also agree with StuRat; the flakes just look dryer to me. SemanticMantis (talk) 21:55, 12 March 2011 (UTC)

Preventing earthquake/Tsunami damage by triggering them?
Can we prematurely trigger e.g., the expected next Cascadia megatrust earthquake, using hundreds of simultaneous underground nuclear explosions along the fault line? Then everyone can be evacuatated well in advance of the event and no one will die. Radiation is contained just as in ordinary nuclear tests, so there isn't a big issue here, it seems to me... Count Iblis (talk) 21:50, 12 March 2011 (UTC)


 * A priori, I would say: 1. It's not clear that you can trigger an earthquake with nukes. Nukes are big on a human scale but not a geologic scale. 2. In the example you give, the fault line is well under the sea floor. That would present a few logistical difficulties to say the least. 3. Radiation is contained when you know what the seismic and geological characteristics of the ground are. (And even then, sometimes mistakes happen.) In this example, you would be trying to affect the geology rather drastically. That seems problematic for containment. 4. The uncertainties are rather gigantic. 5. Politically infeasible. --Mr.98 (talk) 22:47, 12 March 2011 (UTC)


 * Also, the nukes would probably only work to trigger a quake if it was just about ready to go, anyway. And, if we are able to predict that, then we really don't need the nukes, just evacuate everyone when it's ready to go. StuRat (talk) 23:30, 12 March 2011 (UTC)


 * Some years ago I remember seeing or reading something about a situation in the US where water was pumped into or out of the ground, and this had an effect on the rates of minor earthquakes in that area. 92.15.8.206 (talk) 00:27, 13 March 2011 (UTC)


 * You are referring to the Denver earthquakes, where seismicity was triggered by injecting liquid waste into a deep borehole (3671 m) at the Rocky Mountain Arsenal, see here, this was due to changes in the effective stress on existing fault planes caused by increased pore fluid pressures - basically as rocks are more deeply buried they become harder to fault, but if you reduce the confining pressure by pumping fluids in this allows small adjustments on the existing faults to release some of the stored elastic strain energy in the form of earthquakes. Mikenorton (talk) 09:19, 13 March 2011 (UTC)


 * The weight of the water might cause the Earth to compress under it, generating tremors. I recall that Hoover Dam had that effect, as Lake Mead filled with water. StuRat (talk) 00:43, 13 March 2011 (UTC)


 * If you change the load on part of the crust, by filling a large reservoir or by excavating a large mine, you will change the local stress state, potentially triggering an earthquake. Mikenorton (talk) 09:19, 13 March 2011 (UTC)
 * The combined force of the nuclear explosions would need to be at least as great as the tidal forces of the Moon and Sun to trigger an earthquake.predictably. The bomb blasts are impulses that would have to be synchronised and could cause additional havoc by their shock waves. Just the vision of a following radioactive tsunami makes the OP's idea unsellable. Cuddlyable3 (talk) 20:21, 13 March 2011 (UTC)


 * You'd be better off pumping water down to lubricate, rather than nuking. 92.15.11.100 (talk) 12:18, 14 March 2011 (UTC)

Seamounts and faults focus tsunamis?
The map of the calculated wave height for the recent tsunami is intriguing. Obviously, it's a simulation, proceeding from known laws, but is there a shorthand way to understand its prediction?

In particular, there are some general rules that seem to apply to that picture:


 * The waves typically travel in nearly straight lines - red areas don't spread much and attenuate very slowly.
 * When they hit an obstacle they intensify.
 * When they hit a seamount/guyot they intensify in a straight line downrange from it, at least for some hundreds of miles.
 * California and Oregon receive some extra-special exception to this rule, where the wave gets intensified at the Koko Guyot, travels along a ridge to the east of it, then follows a transform fault all the way to North America. (There's another transform fault to the south that seems to get the same treatment, but many others that seem unaffected)

Do any of these speculations of mine actually represent scientifically known rules that we should add to the article about tsunamis? Wnt (talk) 22:02, 12 March 2011 (UTC)


 * Such simulations are not the result of simple applications of physics. They are usually numerical physics models.  I suspect this particular plot is created by measuring peak-wave-amplitude in a full 3-D or 2.5-D numerical wave equation modeling exercise.  Here's a summary of the MOST numerical wave model used to generate the plot you linked.  You can search for prior research-publications on the Pacific Marine Environmental Laboratory tsunami-modeling website, or contact NOAA's researchers for more details of the techniques they use.  Waves behave in very complicated ways when they are injected into a nonhomogeneous environment (i.e., variable sea-depth, sea-temperature, salinity, and any other factors that might affect wave propagation characteristics).  General ideas about constructive and deconstructive interference might help guide your intuition, but in practice, the complex interactions between the wave and its environment defy "simple" rules.  Nimur (talk) 22:55, 12 March 2011 (UTC)


 * Comparison of model data with tide gage data is interesting (for example, the model was off by about 10 cm for high-point and about 30 cm for low-point for San Diego). See also the March 11, 2011 Honshu event at NOAA.  WikiDao    &#9775;  23:14, 12 March 2011 (UTC)


 * Interestingly, the main direction of the tsunami plume pointed toward Southern Chile at a location south of the 2010 Chile earthquake epicentre, which in turn produced a tsunami that pointed south of this year's Japan earthquake. Modelling would also likely take the Coriolis force into account, and the path of Japan's tsunami seemed to follow some bathymetric seamounts and ridges toward Chile. Subsea surface heights are known to affect sea level. ~ A H  1 (TCU) 01:51, 13 March 2011 (UTC)


 * It seems that the simulation is not quite perfect, but I still wonder if a much less sophisticated analysis could be practically useful. For example, if there really are features like transform faults that can aim a tsunami at you, then maybe you could tot up the average intensity of all tsunamis over a century in various coastal towns, and accurately designate "tsunami-prone" areas where you evacuate based on a lower magnitude alert than others.  Or if seamounts really intensify it, then someone in the disaster response office can take a look at the first alert about the position of the epicenter and see if it's on the opposite side of a seamount from where he's standing.  It would probably be good to have some immediate empirical rules to go by to better refine the alert, before getting the full simulation results. Wnt (talk) 07:39, 14 March 2011 (UTC)