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Monday, March 11, 2013

Comet PanStarrs NOW VISIBLE FROM NORTHERN HEMISPHERE INCLUDING INDIA

By
Akshay Deoras

The much awaited Comet PanStarrs is now visible in the Northern Hemisphere including India.
I personally saw the comet through a 7 x 50 binocular from Nagpur,Maharashtra today evening despite of lights,atmospheric haze and a few light clouds.

The city lights and the limited magnifying power of binoculars didn't allow for a detailed view of the comet but I was able to see the giant comet nucleus, the coma around it and the hazy tails.
On Tuesday I will be observing the comet through my Celestron NextStar 80SLT Telescope and get some photos..

Here are some viewing tips if you are planning to watch the comet-

To view the comet, first select a place which is free from the lights like street lights or building lights ( which will give a better view). It's mandatory to select a place which has a clear,unobstructed view of the west side particularly close to the horizon ( atleast 5-6 degrees above the horizon).
After such a place is selected for viewing, one will need good binoculars ( of high magnification power) if observing from city.metro areas. A small sized telescope will be the best to see the comet completely.

The comet will be visible in the lower western sky ONLY AFTER THE SUNSETS. Infact, it becomes visible in about 15-20 minutes after the sunsets. Initially one will see it like a small cloud which is illuminated by sunlight. Later it becomes clearly visible

This comet will be visible through the naked eyes if one observes from light free areas. People from cities may also see the comet by naked eye but it will appear just as a faint dot. Expert sky gazers however will distinguish it.

As the comet lingers in the twilight for around 30 mins after the sunsets, the view doesn't change much until it gets dark.

On Tuesday, 12th March, the comet will be in between 260-265 degrees ( particularly from Nagpur as the below image gives a description of it). It will be roughly above the location where the sunsets. In the below image, I have purposively depicted the situation before the sunset to show that a young,waxing crescent moon will be there in the sky. However it will not be visible tomorrow ( PEOPLE SHOULD NOT MAKE AN ATTEMPT TO SEE THIS MOON THROUGH BINOCULARS OR TELESCOPE AS IT MAY DAMAGE THEIR EYES)

Tuesday, March 5, 2013

Comet PanStarrs comes closest to the Earth today, to be visible from March 10 onwards in northern hemisphere


By- 
Akshay Deoras 


The Comet McNaught in Jan 2007.


 The visuals of the comets like Halley, Hale-Bopp,McNaught generate instantaneously in the minds of the people who have seen them in person! However there are many people (including me) who haven't seen a comet in the sky .The wait to see the comet in the sky seems to be getting over this year when two comets namely Comet PANSTARRS (C 2011/L4) and Comet ISON (C/2012 S1) will provide a celestial treat to the eyes.Comet ISON might be visible to the eyes during later 2013. 

Courtesy nature.com. The relative positions of Oort Cloud and the Kuiper Belt- Wombs of the Comets. 


A comet is a celestial object having three main components prominently when its approaching a star (Say our Sun). The permanent feature with a comet is its nucleus. The nucleus of the comet is made of rocky material,dust,ice,frozen gases like methane,carbon monoxide,carbon dioxide etc having a radius from a few meters to around 30-40km (Although there is no upper limit). The comets are born in either of the two regions called as the Oort Cloud and the Kuiper Belt. The Kuiper Belt is a region which lies beyond the orbit of Neptune within the estimated limits of 30AU to 50AU ( 1AU= 149.6 Million Km) from the Sun. This region has a large amount of objects having composition similar to a comet's nucleus. Dwarf Planets like Pluto also lie in the Kuiper Belt. As this region lies closer to the Sun than the Oort Cloud, it is believed that the short period comets originate in this region. The Oort Cloud (not observed till now) is believed to lie even further away from the Sun and the Kuiper belt at a distance of roughly ~2000AU from the Sun. Due to its distance, its believed that the long period comets like Hale-Bopp were born in this region. As a comet approaches the Sun in its orbit, the heat of the sun coupled with radiation pressure, solar wind etc lead to the sublimation of these volatile materials and a few other things. This leads to the formation of atmosphere type region around a comet's nucleus which is called as "Coma" of a comet. 

The dust tail is colored yellow whereas the ion tail is blue

A comet briefly has two tails (although a rare antitail in some cases)- An ion tail ( made of ions and having its own luminance) and a dust tail ( illuminated by the Sun's light and made of fragments of the nucleus). 

Comet ISON.

Comet ISON's exiting the inner solar system. Above view of the orbit on Dec 11 2013. Courtesy- NASA/JPL


Designated as C/2012 S1 (ISON), Comet ISON is already the most popular comet of this year even when majority of the people haven't seen it in the sky.If you read the related news,you will find adjectives like 'Comet of the century' etc for it. The comet has a nearly parabolic orbit and at present is approaching towards the perigee with respect to Sun ( perigee is a point in the non circular orbit of any object in which it is the closest from that object it is orbiting) which will happen on 28 Nov 2013. This comet has a potential to be visible to the eyes after its perigee. It will all depend on how much it survives the sun. I will write separately on it later this year. 

 Comet PANSTARRS-

Comet PanStarrs from Argentina. Courtesy- Luis Argerich (http://www.luisargerich.com/)

Designated as C/2011 L4, this comet was discovered using the PAN-STARRS telescope at Maui,Hawaii. PAN-STARRS stands for Panaromic Survey Telescope And Rapid Response System-an agency which scans for objects like comets,asteroids in the sky. It was discovered in June 2011. 

On 5th March I.e today, the comet comes closest to the Earth at a distance of 1.097 AU (1AU= 149.6 Million Kilometers).This comet is already visible in the Southern Hemisphere however as it heads  for a perigee with the Sun on 10th March at a distance of 0.30AU from the Sun, it will no longer be visible from the Southern Hemisphere. 


Comet PanStarrs on 5th March. Courtesy- NASA/JPL

From around 7th-8th March, this comet will slowly be visible for the Northern Hemisphere people in the western sky shortly after the sunset. As the comet will be in the lower western sky (after the sunset), it may not be visible through the binoculars or small telescopes as the twilight will interfere with the visibility particularly if observed from any city.The comet will brighten up due to the increased heating by the Sun during the perigee and hence the tails will become brighter from 10th March onwards.



Projected location of Comet PanStarrs on 11th March 2013. The view is for Nagpur,India
( 21.15N,79.09E).

To view this comet, a clear,unobstructed view of the western horizon must be there with a clear sky.People should look slightly above the western horizon shortly after the sunset through binoculars or a telescope ( the ideal location will be a remote place which is free from lights and pollution). The best viewing seems to be during 11th,12th,13th Mar. 

The waxing crescent moon will act as a guide in spotting the comet in the lower western sky from 13th Mar onwards but will interfere with the visibility of the comet. Below image shows the situation of 13th March from Nagpur,India. The moon will be below the comet as seen in the sky with Mars also in a range such that a triangle will form between the three.



On 14th Mar, the comet will appear between the moon and the western horizon and thus will be easy to spot. Below image shows how the young waxing crescent moon with look in the vicinity of the comet.





The comet will be there in the sky (visible to telescopes) throughout the march. However sighting isn't assured then! So  do hunt this comet in Mid March itself!!!


Tuesday, December 18, 2012

The World WILL NOT END on Friday,21st Dec 2012


Published in The Hitavada,18th Dec 2012


Transform Fault at Ngalang

Alutsyah Luthfian | Contributor

Geological Background of Ngalang River


Ngalang River was our second field trip location. It is located in Ngalang Village, Gedangsari District, Wonosari Regency. Using motorcycle, we could reach it from Javan Cultural Centre of Yogyakarta for about, uhm... 2 hours.

What's unique about Ngalang River? In its north - south traverse, the river encompasses four formations respectively (Semilir, Nglanggran, Sambipitu, and Oyo), and the inter-formation contact can be clearly seen. This means, amateur geologists like me didn't waste much sweat there :-D. Have you read my previous post about Watuadeg Pillow Lava? If haven't so, please read it too :-D just to make the whole geological story complete.

The Semilir Formation is composed of tuff, dacitic pumice breccia, tuffaceous sandstone, and shale. This was resulted from a mega-colossal Early to Middle Miocene volcanic eruptions at Parangjoho and Songputri area in Wonogiri, about 30 km to the southeast. Why mega-colossal? The first thing to note is this formation's lateral spread. Unlike a usual volcanigenic geological formation (which can be drawn in one or two quadrangles of geologic map) this Semilir Formation needs four sheets (Yogyakarta, Surakarta, Pacitan, and Ponorogo Sheet), equivalent to > 1000 km2 spread. Another thing to note is this formation's dacitic to andesite rocks, a sign that this formation's magma source was mildly enriched in silica. Those enriched magma might been in the process of cooling (represented by dacite rock), thus it releases gaseous fluid into the chamber and ---- ULTRA PLINIAN ERUPTION!

Beside Semilir Formation, there was deposited Nglanggran Formation. Same with his friend Semilir, this formation is composed of andesite rock. The difference is at the genesis; Nglanggran was deposited by a rather "quiet" volcano, refer to its composition: thick lavas plus some breccias (no tuffs and pumices). The breccias are deposited in deep sea environment, due to its visible reverse bedding. Reverse bedding is a behavior of sedimentation process in which softer sediments are deposited below the coarser one due to turbidite current - a rapid current resulting from very muddy and stony marine landslide. Asking about the source volcabo's dimension ? Never compare it to today's Merapi, it might be as huge as 4,000 or even 5,500 meters (seeing the case of Mount Kenya, prior to its carving by glaciation,the volcano's height was predicted to be 7,000 m). Nglanggran Formation was deposited alternately with Semilir Formation - thus Nglanggran Formation is also from Early to Middle Miocene.

Above the Nglanggran Formation...(Note, just Nglanggran, not including Semilir), deposited the Sambipitu Formation. Sambipitu Formation seems to be deposited in coastal environment, due to its abundance of sand, clay and mud. Some features we can found in Sambipitu Formation is burrow (a hole cutting accross lamination which was dig by animals), mud cracks, and convolute bedding. It was deposited around Middle Miocene.

The latter formation is Oyo Formation. The Oyo Formation is interesting, the lower part is composed of tuff and tuffaceous marl but as you trace it upward it would gradually changes into bedded limestone with some rounded andesite fragments. It might be deposited in continental shelf at Middle Miocene, after Sambipitu. Lack of eruptional-origin materials at Sambipitu and Oyo Formation is a sign of retreating volcanic activity during the course of Middle Miocene.

A crop of Eastern Yogyakarta stratigraphy, made by Surono (1992).

Faulting at Ngalang River


Besides good quality outcrops and inter-formation contacts, other thing can't be missed in Ngalang River is the fault. Based on geological map (released 1992) made by Surono, B. Toha, and Ignatius Sudarno (the latter is my lecturer for structural geology), there is a sinistral transform fault at Ngalang River. Here is the crop of the map.

Dextral transform fault at Ngalang. North is to above.
This is the geologic cross section of Ngalang River made by Anindyo Widiasworo (2011) in his undergraduate thesis. This geologic cross section runs from northwest to southeast and cutting Ngalang River at its mid (see the fault and the first 'S' - stands for 'sungai' or river).
In those cross section, we could see that the eastern part of the sinistral fault is uplifted.
Up to this section, everything is fine. But when going into the realm, my mind = kicked.
Why those should happen ?...
The contact between Nglanggran and Sambipitu Formation. The Nglanggran Formation is dominated with breccias and sandy siltstone . The sandy siltstone is deposited below breccia - a clear example of reverse bedding. The Sambipitu Formation is dominated with softer sediments like tuffaceous siltstone. Photo taken by Annisa Sofhia Pratiwi and delineation by Alutsyah Luthfian. North is to your left.

Explanation from Structural Geology's Eye

The image below may have explained what has happened in Ngalang River.

Another thing to note is the presence of micro-reverse and micro-normal faults at Sambipitu Formation. I will talk about this very later, so stay tune! :-D

Thursday, November 15, 2012

Basalt in Java.

Alutsyah Luthfian | Contributor

Long time not posting there... well I promised myself I will post here after the long, full of romance petrology first field trip. What will I tell you? Something about basalt. You know, in andesitic Indonesian volcanic arc, there is basalt! Truly basalt!


All Starting with Basalt


Long, very long time ago, before Paleogene epoch, the subduction of Eurasian and Australian plate has been started. This made a series of volcanoes in Bangka, Malaysia, and Riau Islands, according to Pupili (1973). The remnants of the volcano is a belt of tin-bearing granite which is mined extensively in some parts of Bangka, Belitung and Riau Islands. However, at the Paleogene (about 60 million years ago), something new was about to happen, south of the old contestant - Borneo.

Basalt lava made its way to the sea bottom, partly because of it is pushed by the subducting Australian Plate, and in another part it may be pushed out by convective flow of magma. The earliest known form of volcanism is Watuadeg pillow lava which crystallized deep in the sea about 56 mya. Basalts tends to crystallize at their time of extrusion because of their very hot temperature (1200 to 1400 K) , which does not allow magma to crystallize before it is extruded. More felsic (acidic) an igneous rock, more time passes between its crystallization and extrusion.
How is Watuadeg pillow lava looks like?



That's the basalt. Looks impressive, isn't it? With cracks in its surface caused by fast cooling, fragile glassy minerals in its surface and fast movement of lava flow. When it is cut latitudinally, we would see concentric rings which mark the changing of rocks composition ; glassy mineral abundance nears the surface and subhedral to anhedral minerals visible in inner part. Subhedral mineral is a mineral in which some of its sides is not perfectly shaped. Anhedral mineral is a mineral in which all of its sides is not perfect. Silicate minerals present in this rock are pyroxene and plagioclase. Pyroxene is black, and plagioclase is slightly transparent. The abundance of pyroxene and plagioclase is 5% and 15%, respectively. Olivine in this rock has been oxidated into Ferric Oxyhydroxide.
The picture below shows pyroxene and plagioclase in basalt rock specimen from Watuadeg. The big, shiny crystal near the left-center of image is plagioclase, more specifically labradorite. Labradorite tends to be more shiny than pyroxene, especially at the cleavage. Labradorite cleaves in good quality (smooth surface) at {001} but not do at {010}. Compared to pyroxene, pyroxene cleaves more clearly and better at that sides. {001} and {010} is Bravais - Miller indices, in which {001} corresponds to crystal face facing in z-direction, and {010} is crystal face facing in y-direction. In Bravais - Miller indices, the x-y axis is rotated 90 degrees counterclockwise.

Geochemical and Tectonic Aspects

In Java Island alone, there are many places in which basaltic pillow lava exposed. I will divide them into two categories, the eastern and western part. The eastern part, comprising Watuadeg, Nampurejo, and some areas to the east of it are the place where pillow lavas exposed without significant deformation. The western part like Karang Sambung and other areas to its west are the place where pillow lavas exposed with significant deformation. The geochemical aspects of western and eastern part is also different.
The main geochemical difference between western and eastern part is the amount of Potassium Oxide of basaltic rock. This Watuadeg pillow lava contains 0.64% Potassium Oxide, while the Karang Sambung one contains 0.28%. Based on the amount of Potassium Oxide, scientists like Kuno (1960),  Bronto (1994), Suparka and Soeria-Atmadja (1991) can determine that Watuadeg pillow lava is a back arc/subduction zone-related volcanism and Karang Sambung is an oceanic ridge-related volcanism.
Back arc volcanism is an evidence of calc-alkaline magma series. Quite a jargon? Yeah, I will explain here. Calc-alkaline magma series is a series of magma evolution ; the first volcanoes give us basaltic magma, then another volcano that erupts much-much later (million years afterwards) give us a more acidic magma, call it andesite basalt. Much later another volcano born and give us andesite. The latter volcanoes , but before the more recent Merapi or Merbabu, gives us diorite. Merapi and Merbabu alone gives us rhyolit. The changing of magma composition from basalt to rhyolit is a sign of silicate enrichment - caused by melting of subducted Australian Plate. The melting itself is promoted not only by heat, but also by seawater that contained in the subducted sediments or seeping in rock cracks/faults. Seawater also carry ions like Potassium to the mantle, that's why subduction related-volcanism typically have higher Potassium Oxide than the ridge-related one.
By being a back arc volcano, this Watuadeg pillow lava is relatively undisturbed by tectonic deformation. The three thing that may disturb him is magmatic intrusion, faulting and acidic water. But knowing that glassy minerals is mostly composed of stable and resistant silica, acidic water can only oxidize and dissolve the olivine inside by means of seeping into rock cracks - creating an interconnected void which later cause some part of rock to detach and lost into sediments around. This mechanism may explain why there is basaltic inclusion in pumiceous sandstone ~5 meters east of it.


What Happened Afterwards

After this extrusion of pillow lava, this pillow lava may be raised up well above his hometown in 2000 meters-deep ocean. This thrusting activity works for so long until this pillow lava is exposed above sea level, where acidic water is abundant. Acidic water carve this pillow lava and deposited the sandstone containing pumice and tuff. The pumice and tuff might be resulted from the slopes of a group of andesitic volcanoes 20 to 50 kilometers SE. The andesitic volcano might have erupted colosally due to very thick volcanic debris deposits. The colossal eruption is due to accumulation of gases during transition from basaltic to andesitic volcanism, which is also the quiet era of Javan Volcanoes. That colossal eruption was happened in Middle Miocene (around 16 to 11 mya).

Sunday, August 26, 2012

RIP Neil Armstrong



Neil Armstrong, the first man to step on the Moon has passed away on 25th August 2012 due to problems relating to the CardiVascular Process

Neil Armstrong will always be remembered for "That ONE SMALL STEP" he took which brought a "GIANT LEAP FOR MANKIND"

Akshay's Gyaan Networks pays TRIBUTE to Neil Armstrong,May His soul rest in a peace and his family come out of the grief!



Astronaut Neil Armstrong



(Image Courtesy- CBS News)

Friday, August 24, 2012

Frequent Above 100 Max monthly SSN ( Smoothed Sunspot No) during Solar Cycle 15-23 AND Solar Activity Update

This week and since a few days earlier, the space weather has been mostly CALM with a remarkable silence from the Sun as no Major Sunspots (Capable of producing a High end Solar Flare) have been noted on the Solar Disc.
Here is a very interesting observation about the Solar Data esp the Max Smoothed Sunspot No from a Solar Cycle 15 to 23

Here is the Smoothed Sunspot No (Monthly basis) during individual Solar Cycle from Cycle 15-23. We had initially thought of Solar Max and Min in a cycle but the non stop high SSN from Solar Cycle 17 to 20 leads us to think whether the solar cycles are related to each other in terms of their max SSN or not.

Solar Cycle Cycle starts Cycle ends Amplitude(yr) Max SSN ( Monthly) Min SSN Spotless days
Solar cycle 15 August 1913 August 1923 10.0 105.4 (Aug 1917) 5.6 534
Solar cycle 16 August 1923 September 1933 10.1 78.1 (Apr 1928) 3.5 568
Solar cycle 17 September 1933 February 1944 10.4 119.2 (Apr 1937) 7.7 269
Solar cycle 18 February 1944 April 1954 10.2 151.8 (May 1947) 3.4 446
Solar cycle 19 April 1954 October 1964 10.5 201.3 (Mar 1958) 9.6 227
Solar cycle 20 October 1964 June 1976 11.7 110.6 (Nov 1968) 12.2 272
Solar cycle 21 June 1976 September 1986 10.3 164.5 (Dec 1979) 12.3 273
Solar cycle 22 September 1986 May 1996 9.7 158.5 (Jul 1989) 8.0 309
Solar cycle 23 May 1996 December 2008 [10] 12.6 120.8 (Mar 2000) 1.7 821

(Source; Wikipedia List of Solar Cycles)

Thus one can infer that since the Solar Cycle 15, the max sunspot no ( monthly) has reached above 100 ( except Solar Cycle 16).

The Solar Cycle 24 so far had the max SSN ( IPS Solar Based) of 96.7 in Nov 2011

The July 2012 SSN has been 66.5 as against the estimated 72.1 . The SSN was 64.5 in June 2012.

Article: Earthquake at 30,000ft above the ground???

I was on my way back to Nagpur on 19th May from Muscat,Oman. The ascend of the flight from Mumbai was pretty smooth. However in the mid way and as we approached Nagpur, the flight experienced a moderate turbulence. Though I am a frequent flyer,that day's turbulence was really a tough one to forget. I was flying in an Airbus A320 aircraft. After a short discussion with my friend Co-Pilot Arpit Gupta who was the Deputy Commander of the same flight,I wrote an article on it.

Already having a meteorological background,it was easy for me to figure out what type of conditions are really needed for such turbulences to occur which makes one feel like Earthquakes even at an elevation of 30,000 ft (Mostly due to the CAT turbulence type or if the flight accidentally enters the Cumulonimbus Cloud System)..

This article this scientifically explains this phenomena of Turbulence...

It was published in The Hitavada on 22nd May 2012

(The CB cloud photo was taken by me on 11th May 2012 while I was enroute to Mumbai from Nagpur)

Article: Guest from the Cosmos in Vidarbha (The Hitavada,5th June 2012)

There was a Meteorite shower around Nagpur region (Referred as Vidarbha) on 22nd May 2012 afternoon. People heard the explosion sounds in the afternoon especially in a wedge area around 100-200kms from Nagpur city.

Surprisingly, an earthquake measuring 2.1M on the Richter Scale was recorded 30km NE of Akola which is near to Nagpur.

The article thus explains the basic difference between a meteorite,meteoroid and meteror in a very simple and illustrative way. Also I have investigated whether the Earthquake was caused to the impact or not (As a few meteorites had produced Earthquakes in the past)

The article was Co-Authored by Me,AKGs Aluth Fian and Mr.Sandeep Shirkhedkar.

I thank them for their support

Times of India interview (20th August 2012)

I was interviewed recently by the reputed newspaper Times of India at Nagpur. I was asked about my work and matters like why I chose to do a BS by going against the stream and why do people opt for engineering more than B.S

It was published in The Times of India,Nagpur on 20th Aug 2012

Article: Ek Mayan Mein Do Fermion??? ( The Hitavada,21st Aug 2012)

Monday, July 16, 2012

General Factorial Formula

Alutsyah Luthfian | Create Your Badge

General Factorial Formula:
\[x\underbrace {!!...!}_n = x\left( {x - n} \right)\left( {x - 2n} \right) \cdot \cdot \cdot a\]
a is the smallest integer, in which $a - n = 0$ or negative numbers.

Tuesday, May 1, 2012

SPECTACLES IN THE UNIVERSE!

 THE HITAVADA,NAGPUR ON 1ST MAY 2012


Here is a view of the latest article titled as " Spectacles in the Universe" which was published in the 1st May 2012 edition of The Hitavada newspaper. The article is on the very basics of gravitational lensing and its analogy to a person wearing specs on the Earth. The article has been co-authored by myself ( Akshay Deoras) and Prof.Shashikumar Chitre ( Dr S.M Chitre) who is Professor Emeritus at the Centre for Excellence in Basic Sciences at Mumbai. 


Prof.Chitre has many years experience in the field of Gravitational Lensing and known for his joint work with Prof.Jayant V Narlikar ( IUCAA) of proposing "The apparent Superluminal Motion in Quasars through Gravitational Lensing" in 1978. 

The idea of writing this article generated in my mind a few days ago ignited by the Public Lecture by Prof.Jayant V Narlikar a few days ago in Nagpur. The article is purposively titled as Spectacles in the Universe as a comparison is made between the gravitational lens and the spectacles of a person which is a convex lens basically.

Following Keywords shall assist the readers to understand the topic-

General Theory of Relativity- Proposed by Albert Einstein in 1916 explains the relation between the Space and Time referred as Space Time with Gravitation. The theory explains how a gravitational mass influence the space-time in the universe consisting of Space-Time Fabrics causing curvatures in the Space-Time called as Space Time Curvature. The theory also proposed that a ray of light will be influenced by this bending of space time causing the light to travel a geodesic path.

Quasar- Quasar stands for Quasi-Stellar Radio Source is a very compact form of the Galactic Nuclei ( roughly the center of galaxy) known as an AGN ( Active Galactic Nuclei). Quasars are being studied and are known to be powered by the accretion ( falling in) of material such as interstellar gas etc. in a black hole ( Supermassive BlackHole) at the centers of Galaxy. Thus mechanism produces a source which generates tremendous emissions especially across the Radio and Visible Spectrum. A single quasar can outshine an entire galaxy.


Einstein Cross,Einstein Ring,Einstein Arc- These are the names given to a specific shaped images of a distant quasar mostly influenced by a gravitational lens like high mass galaxies. 


Extra-solar planet- known as exoplanets which are orbiting distant stars in their respective star-planet system. Its a classical case of Gravitational Microlensing where as mentioned below images ( virtual or real) of the sources aren't produced by there are changes in the intensity of light coming from the source ( similar to astronomical transit). A major difference between astronomical transit and a result of Gravitational Microlensing is that in the case of a transit, an object ( say any heavenly body appearing smaller than the source star) passes infront of the source and hence an observer viewing in the same plane and same axis notices a dim in the light from the source. In the case of Gravitational Microlensing, a star can even pass infront of the source and due to the lensing, the light of the source instead of dimming magnifies... 







Credits-
Prof.S M Chitre
Prof. Jayant V Narlikar
Vikas Vaidya ( The Hitavada)

Wednesday, April 18, 2012

Mineralogy at A Glance

readers, i'm sorry for no pics. Made it in accordance to April 19, 2012 Mineralogy test.


Introduction


Hi readers! This time I wanna talk about mineralogy, uhm, a bit. In geophysics studies, minerals is a speaking stone. It tells us how was a layer of stone formed, what it should countain, and how old is it. A mineral is not eternal; the example being olivine. Olivine is a mineral that formed deep in the basaltic magma chamber. This green, transparent and beautiful mineral is hard. Beside its hardness, when it is put in the river, it would oxidize into another mineral called iddingsite, with different chemical composition than olivine. Another example being graphite that is compressed and heated near earth mantle, after which it changes into diamond. What making minerals ephemeral is simply the geologic processes - it changes the position of minerals in the Earth. For minerals, changing of position also means changing of thermodynamic condition and physical treatment. An igneous stone blasted by volcano, sooner or later would be carried into sea. In the sea, rock powder soon turned into layers of sediment rocks because of pressure brought by water weight. Then the plate tectonic mechanism drive the sediment to the trench and here the sediments are pressed as much as several gigapascals into metamorphic rocks. If lucky, some of the metamorphic rock is lifted again to the earth surface, creating mounts of marbles. If not, it melt again in the astenosphere, becoming magma and repeat the cycle.


How Does Minerals Form ?


Minerals are natural things, so diamonds produced at factory, instead of having near-original diamond qualities, is not called mineral. Because mineral is natural, so its forming process is always natural (not man-made). And also, differ crystal and mineral. We can grow mineral's crystal in laboratory, but we can not call that crystal as 'mineral'. Also, a volcanic lava which cools fast can not make their mineral into crystals - that's why we see igneous rock as black or gray. A black volcanic stone consist mostly of hornblende mineral while the grey one may have more mica or orthoclase mineral content.
Minerals are formed by following ways:
  1. Evaporation from solution.
  2. Gas deposition.
  3. Crystalization.
  4. Growing in solid substance.
  5. Chemical reaction between two different phases.
Explanation below:
  1. Evaporation from Solution
  2. When seawater is flowing into shallow evaporation ponds at morning, it will be heated by sun to a temperature possible for water molecule to break off connection with Na+ and Cl- and fly away to the air. After Na+ and Cl- ion break up with water, they will connect each other again to make NaCl (Halite mineral, common salt). If sea level recedes, more halite is deposited on land, creating salt pan. Sediments may bury the salt pan and geologic process fold that salt layer, because of its elasticity the salt layer may turn into a salt dome and mined by man as rock salt. Another example is calcite in caves, travertine stairs, or blotch of iron rust lining your tap in garden (that iron rust might not coming from your oxidizing tap but from acidic ground water that contain so much Fe2+ ion).
  3. Gas deposition
  4. While volcanic gases out from an erupting volcano, some of its content directly deposit into crystal. The simplest exapmle is sulphur. The deposition of sulphur is reasonable after seeing its phase diagram. Another kind of gas deposition may be occured deep in magma chamber, when bubbles of gas deep from astenosphere enter it and stick with magma chamber's outer stone roof. When sticking with the magma chamber's roof, some mineral in the gas deposited there.
  5. Crystalization
  6. In mineralogy, the term crystallization refers to magma or lava crystalizing when it reaches a spesific crystallization temperature. The magma, liquid form of igneous rock in the depth of earth's crust, crystalization process is so slow that the mineral there can grow into amazing sizes. Why so slow? What makes it slow is because the temperature of magma decreases slowly. The effect is it can maintain a spesific crystalization temperature for a very long time, say it could be hundreds of years. Lava is magma that reaches the earth's surface. Some lava cool fast and some slow, the faster it get cools, the smaller is the crystal size. Obsidian, a stone resulted from fastest cooling lava, has no crystal structure yet it have a vitreous (glassy) look. Andesite, another igneous rock, cools slower; the temperature of its parent lava may be as high as 700o C 2 weeks after the eruption ceased. The effect is andesite's mineral can be barely seen by naked eye. The slowest cooling magma, deep beneath earth surface, producing pegmatite. Minerals composing pegmatite is so big that we can analyze them one by one.
  7. Growing in solid substance
  8. This process is known to metamorphic stones. When a sedimentary or igneous stone is buried deep in earth's crust by means of geologic processes, it would face tremendous amount of heat and torturing gigapascal pressure. This coupled torment mechanism drive the molecules of rock mad. That mad molecules soon adapt to that condition (they surely can go nowhere :-D ) by reconstructing their chemical bond. When they reconstructing, it is the time when a new crystal is grow within the old one.
  9. Chemical reaction between two different phases
  10. When a solid mineral is exposed to some gases or liquid, some or all atom composing that mineral would be exchanged to that gas/liquid. This kind of chemical reaction surely resulted in new mineral with different chemical composition. For example, see the aforementioned olivine case. The hotter the reaction place, the faster it get done -> the concepts of activation energy of reaction.

So the conclusion is, mineral formation is ruled by the change of temperature or pressure surrounding the mineral. In the case of gas deposition and evaporation, the pressure contributing there is atmospheric pressure.
All mineral is starting as a small 3D molecule called nuclei. When surrounding temperature and pressure is suitable for the nuclei, the nuclei started to attract other atom possible for binding with it. The amount of possible atom + speed of temperature change + room provided in the system (remember, there are so many similar nuclei sharing limited place together) determine the shape of mineral. If the room is large, temperature change is slow and possible atom is many, a mineral can grow into a huge, perfectly shaped one.


Types of Mineral


In the earth, there are more than 4000 mineral. Broadly speaking, the 4000 mineral is divided into two main groups, the silicate and non silicate type. Further, the silicate type is divided into six group based on its molecular structure:
  1. Nesosilicates
  2. Silicate minerals composed of separated, alone SiO4 molecule.
  3. Sorosilicates
  4. Silicate minerals composed of paired two molecules of Si2O7 connected at one oxygen atom.
  5. Inosilicates
  6. Divided again into single chain inosilicates and double chain inosilicates. Single chain inosilicates are silicate minerals composed of lines of SinO3n connected at two oxygen atom. The double chain one is simply two opposing single chain connected together.
  7. Phyllosilicates
  8. Chains of inosilicates connected to its neighbors, creating a vast layer of silicate molecules. Each layer is connected to another layer via metallic ions between them.
  9. Cyclosilicates
  10. In this type of mineral, silicate molecule making a closed structure like triangle, square, or hexagonal. Ratio of Silicon versus Oxygen is 1:3.
  11. Tectosilicates
  12. Tectosilicate mineral has wireframe molecular structure; I mean that every silicate molecule bond tight with the other silicate molecule without specific structure, so that tectosilicate can resist weathering and other chemical reaction better.
About 64% of our crust is composed by silicate minerals. About 92% of mineral found in this earth is silicate type.
The other non silicate mineral is divided into 8 groups:
Mineral Group Example Mineral Picture How People Use Them

Oxides Hematite (Fe2O3) Ore of iron
Sulfides Pyrite (FeS2) Known as fool’s gold
Sulfates Gypsum (CaSO4 (+2H2O)) Used to make plaster
Halides Halite (NaCl) Table salt
Carbonates Calcite (CaCO3) Used to make cement
Phosphates Natrophosphate (Na7(PO4)2F.19H2O) Collection
Borates Ulexite (NaCa[B5O6(OH)6].5H2O) Natural Fiber Optic
Native Elements Sulfur(S) An ingredient of drugs and chemicals

Wednesday, April 11, 2012

NATURE SPARES INDIAN OCEAN! TSUNAMI WATCH LIFTED

**** TSUNAMI WATCH LIFTED FROM ALL THE AREAS OF THE INDIAN OCEAN***

**** UNCERTAINTY EXSIST WHETHER THERE WAS A TSUNAMI IN THAILAND ****

**** MULTIPLE LOW INTENSITY AFTERSHOCKS REPORTED AT OFFSHORE WEST COAST OF NORTH SUMATRA***

AKG Seismology Team-

A Major Sigh of Relief!! The Pacific Tsunami Warning Center has lifted the TSUNAMI WATCH from all the areas where it was issued- 

As per the datas from PTWC, A maximum recorded Tsunami height was 3.5ft at Meulaboh,Indonesia. Here is the report- 

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

 GAUGE LOCATION        LAT   LON    TIME        AMPL         PER
 -------------------  ----- ------  -----  ---------------  -----
 MALE MV               4.2N  73.5E  1223Z   0.19M /  0.6FT  06MIN
 GAN MV                0.7S  73.2E  1212Z   0.03M /  0.1FT  48MIN
 HANIMAADHOO MV        6.8N  73.2E  1235Z   0.25M /  0.8FT  06MIN
 PADANG ID             1.0S 100.4E  1208Z   0.09M /  0.3FT  34MIN
 KO TAPHAO NOI TH      7.8N  98.4E  1143Z   0.05M /  0.2FT  06MIN
 ENGGANO ID            5.3S 102.3E  1104Z   0.12M /  0.4FT  04MIN
 TRINCONMALEE LK       8.6N  81.2E  1129Z   0.06M /  0.2FT  16MIN
 TELUKDALAM ID         0.6N  97.8E  1044Z   0.22M /  0.7FT  14MIN
 COCOS ISLAND AU      12.1S  96.9E  1102Z   0.08M /  0.3FT  18MIN
 SABANG ID             5.8N  95.3E  1010Z   0.36M /  1.2FT  06MIN
 MEULABOH ID           4.1N  96.1E  1007Z   1.06M /  3.5FT  12MIN
 DART 23401            8.9N  88.5E  0956Z   0.03M /  0.1FT  06MIN

 LAT  - LATITUDE (N-NORTH, S-SOUTH)
 LON  - LONGITUDE (E-EAST, W-WEST)
 TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
 AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
        IT IS ...NOT... CREST-TO-TROUGH WAVE HEIGHT.
        VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
 PER  - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

However as was mentioned by AKG, Tsunami wave was generated and it reached places like Maldives,Thailand,Australia,Sri Lanka parts ( shown in PINK) in above region in additions to Indonesia.

However at these areas excluding Indonesia region not more than 1 feet of Tsunami wave was reported. The maximum was 1.06M at Meulaboh,Indonesia for 12min at 1007hrs UTC
Disaster preparedness was in full swing across 28 nations including India where people where forced to evacuate areas in Andaman and Nicobar Islands

Its obvious that a significant Tsunami was generated but location remains uncertain!

As of now, Multiple aftershocks have been reported around the epicenter region as shown by the below image

10-degree map showing recent earthquakes
Above- Each Square represents an Earthquake ( or aftershock) The two BIG BLUE SQUARES are the first earthquake (8.6M) and the aftershock of 8.2M... 

THE BIG QUESTION- WHY THERE WAS NO DESTRUCTIVE TSUNAMI??


AKG's Earthquake Expert Aluth Fian informed that this Earthquake was caused due to a transform fault which rarely generate tsunami, because tsunami is mainly resulted from height change dz -> connection to wave equation. 

Thus the plates had more horizontal movement than vertical and hence NO SIGNIFICANT Tsunami was generated. If it hadn't been the Transform Fault responsible then a significant Tsunami would had generated and quite similar to 26th Dec 2004 Event.. 


Aluth Fian shall update on the science behind this soon!


POWERFUL AFTERSHOCK HITS WEST COAST OF NORTHERN SUMATRA

AKG SEISMOLOGY-

*** POWERFUL AFTERSHOCK HITS WEST COAST OF NORTHERN SUMATRA***
*** USGC REPORTS 8.2M***




A STRONG AFTERSHOCK HAS BEEN REPORTED AT 0.773°N, 92.452°E 


AT 10:43:09 UTC


AS OF NOW, TSUNAMI IS HEADING TOWARDS THE THAILAND COAST


*************************************************************************************************************************************

UPDATED INFORMATION FROM PACIFIC TSUNAMI WARNING CENTER IS INDICATING A STRONGER TSUNAMI WAVE THAN THE PREVIOUS HITING INDONESIA COAST

TSUNAMI BULLETIN NUMBER 004
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 1054Z 11 APR 2012

THIS BULLETIN IS FOR ALL AREAS OF THE INDIAN OCEAN.

... AN INDIAN-OCEAN-WIDE TSUNAMI WATCH IS IN EFFECT ...

... A MAJOR AFTERSHOCK OCCURRED AT 11:43Z WITH MAGNITUDE 8.3 ...

A TSUNAMI WATCH IS STILL IN EFFECT FOR

 INDONESIA / INDIA / AUSTRALIA / SRI LANKA / MYANMAR / THAILAND /
 MALDIVES / UNITED KINGDOM / MALAYSIA / MAURITIUS / REUNION /
 SEYCHELLES / OMAN / PAKISTAN / SOMALIA / MADAGASCAR / IRAN /
 UAE / YEMEN / COMORES / MOZAMBIQUE / KENYA / TANZANIA /
 CROZET ISLANDS / BANGLADESH / KERGUELEN ISLANDS / SOUTH AFRICA /
 SINGAPORE

THIS BULLETIN IS ISSUED AS ADVICE TO GOVERNMENT AGENCIES.  ONLY
NATIONAL AND LOCAL GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKE
DECISIONS REGARDING THE OFFICIAL STATE OF ALERT IN THEIR AREA AND
ANY ACTIONS TO BE TAKEN IN RESPONSE.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

 ORIGIN TIME -  0839Z 11 APR 2012
 COORDINATES -   2.3 NORTH   93.1 EAST
 LOCATION    -  OFF W COAST OF NORTHERN SUMATRA
 MAGNITUDE   -  8.7

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

 GAUGE LOCATION        LAT   LON    TIME        AMPL         PER
 -------------------  ----- ------  -----  ---------------  -----
 TELUKDALAM ID         0.6N  97.8E  0952Z   0.15M /  0.5FT  08MIN
 SABANG ID             5.8N  95.3E  1010Z   0.36M /  1.2FT  06MIN
 MEULABOH ID           4.1N  96.1E  1007Z   1.06M /  3.5FT  12MIN
 DART 23401            8.9N  88.5E  0956Z   0.03M /  0.1FT  06MIN
 SABANG ID             5.8N  95.3E  0956Z   0.31M /  1.0FT  08MIN

 LAT  - LATITUDE (N-NORTH, S-SOUTH)
 LON  - LONGITUDE (E-EAST, W-WEST)
 TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
 AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
        IT IS ...NOT... CREST-TO-TROUGH WAVE HEIGHT.
        VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
 PER  - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

 NOTE - DART MEASUREMENTS ARE FROM THE DEEP OCEAN AND THEY
        ARE GENERALLY MUCH SMALLER THAN WOULD BE COASTAL
         MEASUREMENTS AT SIMILAR LOCATIONS.

EVALUATION

 SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY
 ALREADY HAVE BEEN DESTRUCTIVE ALONG SOME COASTS.

 BASED ON THESE DATA THE THREAT CONTINUES FOR ALL COASTAL AREAS OF
 THE INDIAN OCEAN. FOR THOSE AREAS - WHEN NO MAJOR WAVES HAVE
 OCCURRED FOR AT LEAST TWO HOURS AFTER THE ESTIMATED ARRIVAL TIME
 OR DAMAGING WAVES HAVE NOT OCCURRED FOR AT LEAST TWO HOURS THEN
 LOCAL AUTHORITIES CAN ASSUME THE THREAT IS PASSED. DANGER TO
 BOATS AND COASTAL STRUCTURES CAN CONTINUE FOR SEVERAL HOURS DUE
 TO RAPID CURRENTS.  AS LOCAL CONDITIONS CAN CAUSE A WIDE
 VARIATION IN TSUNAMI WAVE ACTION THE ALL CLEAR DETERMINATION MUST
 BE MADE BY LOCAL AUTHORITIES.


STAY TUNED FOR UPDATES AT

http://www.facebook.com/pages/Severe-Solar-Weather-forecast/112556765473804

Date and Time