Astrology and Earthquake Prediction By Mumbai Engineer

Sometimes I am left shaking my head with disbelief at the rubbish that people try to pass off as science. DNA has a story of Mr. Amit Dave a BMC engineer who has put forth a new earthquake prediction method using the alignment of planets in the solar system as a guide. Yes, astrology now enters the field of earthquake prediction. According to him plate tectonics has nothing to do with earthquakes, it is all in the planetary positions. And its not just earthquakes, but hurricanes and floods too pay obeisance to the remote planets. Mr. Dave, and I found this hilarious, was recently transferred from the Mumbai disaster management cell (hey wait, this man needs to be made chief of the disaster management cell if he can really predict disasters), says that he has not yet predicted the next occurrence (surprise surprise) and needs time to work out this theory (he's been working at it since 1993). But Dave claims that several big earthquakes in the past occurred when the moon and Jupiter and Saturn were in "potent" positions. By the way this is not the first time someone has claimed a relation between the planetary positions and earthquakes, so Mr. Dave does not have a claim to priority here. But I think it is important to point out that claims that have appeared in literature on planetary influence on seismicity have been carried out on small data sets and seem to show an apparent relation with very shallow, small seismic events in continental volcanic regions (Mammoth Lake California) or along mid ocean ridges but these correlations break down for larger data sets and for larger earthquakes. Here is Mr. Dave's "theory" as reported by DNA:

The earth consists of a thin upper crust and molten lava, magma. The inner crust is semi-solid and hot. Like tidal waves, this molten lava is also influenced by tidal currents. The moment the high tide pull is more, it breaks open the crust and earthquakes occur. If the crust breaks completely, it results in a volcanic eruption. Dave says the most potent quakes occur when the sun, Jupiter, Saturn, and the moon are in mutual potent positions like 0º, 90º, 180º, and 360º. The two planets change their direction of motion from direct to retrograde from time to time. The gravitational pull exerted on the earth by this movement induces a change in momentum, mass and velocity of the molten lava, creating disturbances.

There is just so much wrong here that is is difficult to know where to start. Let's start with the forces involved. In typical pseudo-science fashion, Mr. Dave has done a lot of arm waving regarding planetary positions but there is no mention of actual forces involved and whether they might cause damage to the earth. Turns out they cannot. The gravitational force of the moon that an object on earth experiences is only a tiny tiny fraction of the earth's gravitational pull on that object. That means that the miniscule additional force of the moon is simply not enough by itself to create large enough stresses within the earth to break and rupture rocks in the interior of the earth. Bad Astronomy has a detailed calculation of the forces exerted by the moon, sun and other planets in the solar system. "The force of the Moon on you is only about 0.000003 times the Earth's. For me, that means I weigh an extra 0.0009 pounds more when the Moon is under my feet versus when it's on the horizon (and therefore not contributing to the downward pull of the Earth)." Other planets contribute even less and the effect of tidal forces is even tinier than gravity. The entire article is worth reading. I doubt if Mr. Dave read it. Practitioners of psuedo-science never go into the trivial details of actually understanding forces and mechanisms. They only use jargon to impress. Now, the moon does deform the earth slightly in 12 hour semi-diurnal cycles called solid earth tides. But long term monitoring of these cycles and earthquakes has shown no significant correlation between solid earth tides and large earthquakes. Dave makes much of the influence of Saturn and Jupiter but calculations show that the combined influence of all the planets in the solar system is about 1 billionth the influence of the moon. So, no "potent" alignment of planets will make any discernible difference. Which brings me to my second point and the link between earthquakes and magma that Mr. Dave makes. Mr. Dave's theory requires that there be magma in the region where earthquakes occur, since his mechanism of earthquakes is that molten material in the earth's interior is pulled by the moon and other planet's gravity and that causes the magma to break the crust. Just to clarify, the earth's crust does not contain a uniform layer of molten material. Magma occurs in discrete magma chambers localized mostly along plate boundaries and zones of anamolous mantle heat flow within plates, such as beneath the Hawaian islands. I just made a list of big earthquakes in Asia that have occurred in recent memory. Koyna 1967, Kinnaur H.P. 1975, Uttarkashi 1991, Killari 1993, Bhuj 2001, Kashmir 2005, Sichuan 2008. All of these measured more than 6 on the Richter scale. None of them are associated with recent volcanism nor is there magma underneath these locations. We know that by studying the pattern of seismic wave propagation through the earth's crust. These studies indicate only solid crust. Only crustal stresses set up by the larger plate tectonic configuration in the region can explain these earthquakes. Mr. Dave badly needs a lesson in basic geology and plate tectonics. He seems completely ignorant of how the earth works geologically.

By a coincidence or call it the favorable alignment of planets, along with Mr. Dave's public announcement came the news that geologists have drilled and recovered core material from the San Andreas fault zone, one of the most earthquake prone region in the world. And guess what? No magma there either. But as predicted by plate tectonic theory, evidence of rocks crushed and sliding past each other due to the relative movements of the Pacific and North American plates.

I think one of the reasons why people readily believe such claims is that it can be shown that some past big earthquakes did occur when planets were aligned in preferred positions. I don't doubt that. If you go through a list of several thousand earthquakes a few are bound to coincide with whatever planetary alignment that you deem to be potent. The mistake is to ignore one of the most basic rules of statistical analysis which is correlation need not mean causality. Just because two events are coincident there does not have to be a cause and effect relationship between the two. Planets may have been aligned in a certain way when the Sichuan earthquake took place but that does not mean they caused it. Mr. Dave's "theory" lacks a workable mechanism. Only plate tectonics and internally produced stresses can provide it. Reading articles like these really make me mad. But I am mad more at the media than at Mr. Dave. I mean kooky theories are proposed by people all the time. But doesn't the media, in this case DNA have some responsibility in being more selective in the manner by which they publish such claims? Our media is too hooked on to sensationalism and does not take it's role of reporting science seriously at all. It's reporters have not training in science and are too ill prepared, uncritical and gullible, unable to distinguish between quackery and valid science, which is a real shame since most people in India get their science news from such newspaper articles.

Update: Mr. Dave left some questions for me in the comments section. I have answered those in a separate post: Geology Lessons To An Astrologer

Disclaimer Sept. 17: Contrary to some comments left on this post I did not predict the Sept. 17 earthquake which occurred in the Satara district of Maharashtra. Nor did anyone else. Don't let people fool you otherwise. You have to give accurate location information (latitude and longitude) along with a hypothesis in terms of geological forces and stresses acting at that location why an earthquake is likely or imminent. Simply saying that an earthquake will occur on this day and time does not qualify as a prediction. The reason is that there are plenty of earthquakes occurring everyday on earth. On average about 10-11 earthquakes of 6-7 magnitude occur every month, 3 earthquakes of 5+ magnitude occur everyday and more than 20 earthquakes of 4+ magnitude occur everyday somewhere on earth. Without a location and a justification "predicting" an earthquake is easy!! :-)

I'll be writing a larger post on this later maybe in a couple of weeks. Do visit again.

Update: Was September 08 Earthquake Month?

Afforestation Hoax in Madhya Pradesh

India Together has an article by Himanshu Upadhyaya on afforestation measures by the Madhya Pradesh government and how they fall significantly short of their intended targets. The article summarizes an audit by the Comptoller and Auditor and General (CAG) on the diversion of forest land for non forest purposes and the mandatory compensatory afforestation measures taken thereafter and comes up with a depressing but not entirely unexpected finding:

Since the coming into force of the Forest (Conservation) Act, Madhya Pradesh has diverted 51,018 hectares of forest land for non-forest purposes for some 734 projects. While as per the provisions of the Act, the state needed to carry out compensatory afforestation on 73,213 hectares of land as mitigation measures, audit scrutiny of the records in nodal office revealed that as on June 2006, compensatory afforestation has not been carried out at all in the case of 289 projects (39 per cent shortfall at projects level) and on 13,441 hectares of stipulated land (18 per cent shortfall at land covered) after having been unable to utilize Rs.82.60 crores (75 per cent shortfall on utilisation of funds) recovered from user agencies towards the same.

The article points out the many irregularities involved in the compensatory afforestation program. A while ago I wrote a series of posts on deforestation in India's many forest reserves and wildlife sanctuaries. Using the biannual forest survey by the Forest Survey of India and some readily available satellite images I had pointed out that prime wildlife habitats in many tiger sanctuaries have lost forest areas and that afforestation is being carried out without an ecological and bio geographical context. That was based on the 2003 survey. The latest survey made available depicting the situation in 2005 also shows that out of the many forest categories dense forests suffered the most losses. This is almost inevitable considering that riverine basins where big dams come up tend to contain particularly rich dense forests and timber leases are also given in forests with high density of large trees. Additional loses are due to encroachment and clearing of forest for agriculture, mining and freak events like fires. Incidently check out this article on how compensation for ecological losses due to forest submergence is being decided and how developers come up with innovative ways to minimize their responsibility. Currently the total forest cover in India stands at around 20% of the geographic area. The government wants to increase it by around 5% during the 11th 5 year plan. While this is a laudable goal, the implementation resembles more a blind pursuit of statistic, turning our afforestation programs into a book keeping exercise, losses of prime bio diverse forests being compensated with monocultures in many cases far away from areas that need forest cover and forest corridors and webs essential for maintaining viable animal populations.

This audit shows that even those ill thought out afforestation programs are failing miserably. Go take a look at the article and the CAG report. The shoddy ineffectual half hearted approach of the Madhya Pradesh government simply highlights how badly we understand the term "development".

Email Reticence Costs Me A Spot on BBC

Should I now start obsessing over my email? I check mail once or twice a day. I don't have email alerts set up on my computer and I generally have an attitude that just because you can send me a message almost instantaneously don't expect me to reply in an instant. But all this has cost me a spot on the BBC world service twice! They run a show entitled World Have Your Say where listeners and invitees can discuss the topic on hand. I am on their list as a science and technology blogger and have received invitations to join the show, except that both times I didn't check my mail in time. It happened a few months ago when they ran a show on climate change and then again yesterday when the topic was Do You Want More Space meaning "Is space exploration a good investment". I am visiting my sister in Washington D.C. and I blissfully spent Memorial day in the great outdoors munching on burgers and spicy Thai chicken. World Have Your Say somehow muddled along without my inputs.

Having covered my ass with this explanation, now the confession. I am somewhat relieved I didn't make it to the show. See, I am not a few minutes sound byte kind of guy. I don't do too well when people ask me a question followed by a "Your time starts now!" So, I am not sure how well I would have presented my views on that show. Should we invest in space exploration? I don't see how this question is really different from the more general question on whether we should invest in science that may not give us an immediate payoff. Should all funding be only for applied sciences where future industrial, medical and other benefits are clearly definable? Should pure sciences, or projects where the benefits are difficult to quantify be continued to be funded? My answer has been and always will be an unambiguous YES. There is a more philosophical argument that humans are the most curious of all primates, always wanting to see over the real and metaphorical horizon. Exploration of all kinds just for the sake of knowledge is an important part of being human, and this drive to know more simply cannot be shut down based on purely economic arguments. But there are good practical arguments too for continuing to fund science without immediate payoffs. Unanticipated spin offs is a general way for justifying this expense. Space exploration in fact offers a great example of this. It epitomizes the philosophical argument of funding science for the sake of "the need to know what is beyond" and bolsters the practical argument since the benefits of myriad theoretical, technological and engineering breakthroughs achieved in the long R and D space programs of various countries have eventually made their way into society as applications of various kinds. Check out this NASA spin off website which details the range of industry areas that have commercialized NASA technology intially developed for the purpose of space exploration. Within the broad area of funding space exploration one can always argue for funding one specific project over another based on merit but to ask a question whether space exploration itself should be funded is to put limits on our imagination and constraints on future benefits. India's space program so far has been of the applied kind, more geared towards earth applications than space exploration. It too has led to societal benefits most notably in meteorology and natural resource applications and transfer of technology. A recent post claims around 268 technology transfers to Indian industry from India's space program. I found some informative articles related to the economic benefits of the program here and here.

The question "Is Space Exploration a Good Investment" is of relevance now to India as it prepares to launch the unmanned Moon mission, its first real space exploration project. Will there be benefits from this or should we use that money for other "more practical purposes". To me the benefits are already accruing even before the launch. NASA is collaborating in this project by contributing three sensors and no doubt some knowledge transfer as well. Several other European countries are contributing other types of sensors. Indian space scientists have long been an isolated bunch and such collaborative ventures can only benefit us in terms of expanded perspectives, knowledge and technology transfers. Contrary to perception that the project is exorbitantly expensive it takes up a fraction of the total ISRO budget, about 2% of the total outlay in the 10th five year plan.

Could I have said all this on my two minutes to fame spot on the BBC. I doubt it. It took me 30 minutes with a tea break to dish this out :-)

Crustal Flow, Eastern Sichuan Earthquake China

Its been 10 days or so since the big earthquake in the eastern part of Sichuan province China and I haven't come across anything like a good geological explanation in the Indian media. So here is a quick summary. The earthquake measuring 7.9 on the Richter scale occurred at a depth of about 19 km most likely along the NE trending Longmenshan fault which is a long thrust fault marking the boundary between the eastern Tibetan plateau with the Sichuan basin. Seismological analysis indicated that the fault shearing occured in two stages. First, a 100 km long section sheared upto 7 metres and then to the northeast of this another 150 km section sheared about 4 metres. The map below show seismicity since 1990. You can see a concentration of brown dots marking earthquakes arranged in a linear fashion trending NE just at the boundary between the pale yellow region which is the Sichuan basin and the light brown region which is the Tibetan plateau. This marks approximately the zones of disturbance along the Longmenshan fault. The unusually large brown dot is the location of the big earthquake.

Source: USGS Earthquakes

In geology 101 we learn that most earthquakes take place at plate boundaries where the crust is being stressed and actively deformed. Earthquakes away from plate boundaries are not uncommon though. In India in recent memory the two big earthquakes around Bhuj Gujarat and Killari Maharastra are example of earthquakes which took place a long distance away from plate boundaries. The reasons for these intra-plate earthquakes can be usually traced to stress transmitted across plates from zones of plate boundary interaction. The Indian crust in under a compressional stress regime resulting from the collision of India with Eurasia. These compressional stresses can reactive ancient zones of weakness within the Indian plate causing slippage along old faults resulting in earthquakes. The Bhuj earthquake is thought to have occurred along zones of crustal weakness which originated during Mesozoic rifting and basin formation in the Gujarat region of India. Geologic studies show compressional ridges following the same trend as ancient graben structures suggesting that pre-existing zones of weaknesses are now being reactivated like old injuries flaming up during periods of stress. The reason for the Killari earthquake is less clear but a fair guess is that the Deccan Traps at that location sits on very ancient zones of weakness in the Indian crust which originated during the formation of Proterozoic mobile belts of south India. Just like the Indian plate, the Tibetan plateau which is part of the Asian plate, is also under a compression stress regime imposed by the continent-continent collision of India with Eurasia. Although some distance away from the zone of collision, the earthquake at Sichuan needs to be understood in this larger plate tectonic context.

Imagine a square block of dough say 6 inches thick and a foot across representing the Tibetan plateau. Now if you place one hand against one side of the square and drive your fist slowly into the dough from the other side, the dough will respond by thickening and also flowing in a direction perpendicular to the direction of the force you are putting against the dough. The dough has accommodated the shortening by thickening and flowing laterally. That is more or less what is happening to the Tibetan plateau is response to the NNE -SSW compressional stresses imposed by the plate collision. As India penetrates into Asia, the thick crustal material on the Asian plate is flowing eastwards out of India's path. Dont be misled by the term flow. The crust is not flowing like a liquid. The upper crust does break in a brittle manner and easterly movement (flow) of Tibetan crust occurs along faults in this case strike slip and normal faults . At depth the lower crust deforms as a continuous medium more like the dough model I presented. The rates of flow are a few 10's of mm per year. In a recent study by a group of Chinese and American geologists, a array of Global Positioning System locations measuring crustal velocities all over the Himalayas and the Tibetan plateau shows this flow of Tibetan crust with remarkable clarity. See map below. Thin blue arrows denote crustal velocities and direction of flow. Northerly flow dominates in the south central part of the Himalayas and the Tibetan plateau. Further north and east the crust is flowing eastwards towards Sichuan and rotating clockwise and flowing southerwards along the eastern syntaxis of the Himalayas.

Source: Continuous Deformation of the Tibetan Plateau from global positioning system data

I really like this depiction of plate movements. The simple arrows and a land cover map draped over a topographic relief model of the earth helps you vizualize continental scale crustal flow and the resulting deformation of the earth's surface into the many crinkles, wrinkles and elevated areas, something that is not always easy to achieve with geological maps cluttered with necessary but utilitarian symbology. Coming back to the tectonics, this easterly flow of the Tibetan crustal material comes up against stronger crust in the Sichuan basin area. The resistance between the Sichuan basin and the Tibetan plateau results in compressive stresses and thrust faulting along the boundary between the two crustal blocks. The Longmenshan fault is one such thrust fault zone along which the Tibetian plateau is riding over the Sichuan basin. A more conventional map below shows the various tectonic features and fault movements in the Tibetan plateau and along its margins. Blue arrows indicated compression and shortening along the margins of the plateau. Purple arrows indicate shortening in the interior of the plateau. Open black arrows indicate relative motion of crust with respect to stable Eurasia.

Source: Continuous Deformation of the Tibetan Plateau from global positioning system data

So the short answer to why was there an earthquake in eastern Sichuan would be that the earthquake was a result of the building up of stress along the Longmenshan fault in response to the convergence of the Tibetan crust against stronger crust underlying the Sichuan basin. High population density, poor construction and environmental damage in the form of deforestation has led to extraordinary losses in terms of lives and property. It could have been worse. Chengdu, a city of 4 million is just 60 km southeast of the epicentre but may have been spared more extensive damage since it sits of the less disrupted footwall of the longmenshan fault and also because the northeast rupture direction of the fault put most of the rupture energy away from Chengdu. Large areas of China , southeast Asia and India fall under high seismicity risk zones. Often the remote locations and steep terrains especially in the Himalayan and Tibetian regions exacerbate the damage by making rescue efforts difficult . A more rigorous and structured earthquake damage management and mitigation plan needs to be put in place. But I sometimes wonder if scientific risk assessement whether of earthquakes or hurricanes will make any difference to human habitation patterns. By choice people are moving in large numbers to live next to active faults like the San Andreas in California or in the path of hurricanes as in Florida and Louisiana. In the Himalayas and Tibet people have little or no choice on where to live. Regardless of the risks they live where they have always lived on their ancestral lands. I don't see that pattern changing in the near future. NPR has USGS seismologist Walter Mooney giving a good talk on predicting aftershocks or rather how there is no real way to predict them and how stress changes along the Longmenshan fault zone after the big earthquake can trigger later earthquakes.

Groundwater Under The Sahara and Thar Deserts

From NPR Science Friday (I've been getting a lot of material from NPR of late) a discussion of a study that tracked the desertification of the Sahara using palynological evidence from sediments of Lake Yoa. The study suggests that desertification was a gradual process taking thousands of years, apparently contradicting earlier work which relied on evidence from the Mediterranean sea and indicated that desertification was rapid, probably taking place in a few hundred years. What was of interest to me was the talk about massive amounts of groundwater in the Nubian sandstone buried under the Sahara sands. This sedimentary aquifer which is made up of sedimentary sequences ranging in age from lower Paleozoic to the Cretaceous was last recharged in the early Holocene period when the climate in the Sahara region was much wetter. The aquifer contains an estimated 150,000 cubic km of water and currently about 6.5 million cubic metres per day are being extracted over its entire extent covering parts of Sudan, Chad, Libya and Egypt.

I am thinking of the situation under the sands of the Thar desert and see some parallels. I wrote about the recognition of paleochannels associated with the Ghaggar river system in the Jaisalmer district of Rajasthan. These channels contain groundwater which also like the Sahara was last recharged in the early part of the Holocene when this part of Rajasthan was wetter. The ancient river system is thought to have dried out by around 2500 B.C. due to aridification of western Rajasthan. There are grand plans today to exploit these water resources by targeted drilling, i.e identifying ancient river channels and drilling into them. Besides paleochannels it is entirely likely that the bedrock below the Thar sands may also contain aquifers. Recognizing these aquifers is going to be more difficult than paleochannels which show up as distinct linear features in radar images. What is important here is that we realize that just like the Nubian aquifer system this water under the Thar desert, stored either in ancient river channels or bedrock , is currently a non-renewable resource and draw up plans of exploitation with that in mind. As part of the Indira Gandhi Nahar Project (IGNP), the government wants to extend the canals of the Punjab into Rajasthan and use excess water from the Sutlej, Yamuna and the Ghaggar to recharge these potential aquifers. The aquifers will act as giant underground storage tanks, potentially advantageous over new surface water storage areas since no land will be submerged and losses due to evaporation minimized. This is a geo-engineering plan on a massive scale and will likely face a long period of opposition from environmentalists and economists. It might take a couple of decades for the benefits of this project to be realized if geologists and hydrologists ascertain that it makes sense in the first place. Meanwhile it won't take much to start sinking tube wells in the paleochannels and pumping out water from aquifers which have at present no natural recharge potential. Undue haste in exploiting this resource might degrade the system beyond repair. I am not at all certain given the water scarcity in this part of Rajasthan that politicians will show the necessary patience until science determines a sustainable water management plan. Global warming is expected to reduce the supply of water to north Indian rivers from Himalayan glaciers in the future. A planning commission report on water resources which did not take into account the projected shortfall from glacial sources finds

“Currently, total water use (including ground water) is 634 BCM (billion cubic metres), of which 83% is for irrigation. The demand for water is projected to grow to 813 BCM by 2025 and 1447 BCM by 2050, against utilisable quantum of 1123 BCM – 690 BCM from surface water and 433 BCM from ground water. Clearly, the overall demand will outstrip availability in another 35 to 40 years, while ground water in particular will come under even greater pressure in the intervening years.”

Global warming will likely make the situation even worse than the official projections. The non-renewable water resources under the Thar desert will gain even more importance given the expected scarcity of water resources in the Gangetic plains. They will have to be managed carefully.