నెట్ స్వేచ్ఛ

నెట్ స్వేచ్ఛ

ఇంటర్‌నెట్ సమానత్వ వేదికగా ఉండాలంటూ లక్షలాది మంది నెటిజన్లు టెలికం నియంత్రణ సంస్థ (ట్రాయి)కి తమ అభిప్రాయాలు వెల్లడించడం ప్రజల్లో పెల్లుబికిన చైతన్యానికి సూచన. ఇప్పటి వరకు ఇంటర్‌నెట్ ఎటువంటి అడ్డు లేకుం డా సమాచారాన్ని గ్రహించడానికి ఉపయోగపడుతున్నది. ఏ సైట్, ఎవరు యూజ ర్, ఏ సమాచారం అనే దానితో సంబంధం లేదు. చిరు వ్యాపారం చెట్టంత ఎదగడానికి, సృజనాత్మకత వెల్లివిరియడానికి ఇంటర్‌నెట్ వేదికయింది. గూగుల్, ఫేస్‌బుక్ వంటి సంస్థలు చిన్నగా మొదలై, భారీ సంస్థలుగా ఎదగడానికి ఈ పరిస్థితులే కారణం. కానీ ఇంటర్‌నెట్‌లో ఇటీవల ఒక వికృత పోకడ చోటు చేసుకోబోయింది. దీనివల్ల డబ్బు చెల్లించే బడా సంస్థల వెబ్ సైట్లను మాత్రమే వేగంగా అందుకునే అవకాశం ఉంటుంది. ఉచితంగా లభించే కొన్ని సాంకేతిక ప్రక్రియలు (అప్లికేషన్లు) డబ్బు చెల్లిస్తే తప్ప లభించవు. క్రమంగా విలువైన సమాచార గనులకు ఇంటర్‌నెట్ సర్వీసు ప్రొవైడర్ (ఐఎస్‌పీ)లు కాపలాదారులుగా మారిపోతాయి. ఇట్లా ఐఎస్‌పీ లు ఇంటర్‌నెట్‌లో అంతరాలు సృష్టించకుండా చిలీ ప్రభుత్వం ఇప్పటికే చట్టం చేసింది. అమెరికాలోనూ ప్రజల ఆందోళన మూలంగా ఒక చట్టం అమలులోకి వచ్చింది. యూరప్‌లో గతంలో చేసిన చట్టాన్ని సమీక్షిస్తున్నారు. మన దేశంలో ఎటువంటి విధానం అమలు చేయాలనే విషయమై ట్రాయి ఇటీవలే ప్రజల అభిప్రాయాలు కోరింది. దీంతో నెట్‌లో అంతరాలు లేకుండా సమానత్వం (నెట్ న్యూట్రాలిటీ) పాటించాలని లక్షలాది మంది తమ అభిప్రాయాలు వెల్లడించడం విశేషం. ఇంటర్‌నెట్‌లో సమానత్వం పాటించాలనే విషయమై దేశంలోని నెటిజన్లు భారీ ఎత్తున స్పందించడం హర్షణీయ పరిణామం. అయితే ఇప్పుడు తొలగిపోయింది చిన్న ప్రమాదం మాత్రమే. డిజిటల్ సమాచారాన్ని నియంత్రిం చే, డిజిటల్ విజ్ఞానం ద్వారా సమాజాన్ని నియంత్రించే అసలు ముప్పు ఇంకా పొంచి ఉన్నది. దీనిపై ఈ దశలోనే నెట్‌ను ఉపయోగిస్తున్న విద్యావంతులు అప్రమత్తం కావలసి ఉన్నది. ఈ కాగితాల కాలం ఎక్కువ రోజులు ఉండదు. ఇప్పటికే సమాచారమంతా డిజిటల్ రూపంలో నిక్షిప్తమవుతున్నది. భవిష్యత్తులో సమాచారం సేకరించాలన్నా, విజ్ఞానం సంపాదించాలన్నా, పరిశోధన చేయాలన్నా డిజిటల్ రూపంలోని సమాచారమే ఆధారమవుతుంది. ఈ డిజిటల్ లైబ్రరీలను కొన్ని సంస్థలు తమ పిడికిట బిగించి పెట్టుకుంటే పేద వారికి విజ్ఞానం అందుబాటులో ఉండదు. ధనవంతుల చేతిలో విజ్ఞానం బందీ అవుతుంది. ఇదే విధంగా డిజిటల్ సాధనాలతో మనిషిని పసిగట్టి అసమ్మతిని అణచివేసే రాజకీయ విధానాలు రాకుండా కూడా అడ్డుకోవడం అవసరం. నాడు పారిశ్రామి విప్లవమైనా, నేడు డిజిటల్ విప్లవమైనా- విజ్ఞాన శాస్త్ర అభివృద్ధిని హర్షించవలసిందే. అదే సమయంలో ఈ విజ్ఞానం ఎవరి ప్రయోజనాలను నెరవేరుస్తున్నదనే ప్రశ్న కూడా విస్మరించలేనిది. డిజిటల్ ప్రపంచంలో ఈ గుత్తాధిపత్య పోకడను ముందే పసిగట్టి ఎదిరించిన అమెరికా మేధావి, నెట్ కార్యకర్త ఆరాన్ స్వార్‌ట్జ్ బలిదానం ఈ సందర్భంగా గుర్తు చేసుకోవాలె. ఆరాన్ స్వార్‌ట్జ్‌కు బాల మేధావిగా గుర్తింపు ఉన్నది. ఆరెస్సెస్ వెబ్ ఫీడ్ ఫార్మాట్, మార్క్‌డౌన్ పబ్లిషింగ్ ఫార్మాట్, రెడిట్ సోషల్ న్యూస్ సైట్ రూపకల్పనలో ఆయన భాగస్వామ్యం ఉన్నది. అయితే అంతకు మించి నెట్‌ను రాజకీయ దుర్మార్గాన్ని వెంటాడడానికి ఉపయోగించుకోవడం ద్వారా పోరాట యోధుడయ్యాడు. కోర్టు దస్తావేజులను మూల్యం చెల్లిస్తే తప్ప చూడలేని వ్యాపార కుట్రను కనిపెట్టి, ఆన్‌లైన్ ద్వారా వాటిని బహిర్గతం చేశాడు. ఇంటర్‌నెట్ సెన్సార్‌షిప్ చట్టానికి (సోపా) వ్యతిరేకంగా పోరాడి దానిని నిలిపివేయించడంలో కీలక పాత్ర పోషించాడు. పరిశోధనా పత్రాలను గోప్యంగా పెట్టి ధనవంతులకే అందుబాటులో పెట్టడాన్ని ప్రశ్నించాడు. ఈ క్రమంలో మందుల కంపెనీలకు, పరిశోధనలకు గల అక్రమ బంధాన్ని బయటకు లాగాడు. పరిశోధనా పత్రాలు అందరికీ అందుబాటులో ఉండాలనే తన ఉద్యమంలో భాగంగా- ఒక సంస్థ వెబ్ సైట్ నుంచి పరిశోధన జర్నల్స్ భారీ ఎత్తున డౌన్‌లోడ్ చేసుకున్నాడు. ఈ కారణాన్ని చూపి ప్రభుత్వం ఆయనపై ఉక్కు పాదం మోపింది. భారీ జరిమానాతో పాటు ముఫ్ఫై ఏండ్ల ఖైదు చేయడానికి అభియోగం సిద్ధం చేసింది. ఓపెన్ లైబ్రరీ ఉద్యమాన్ని నడిపి, క్రియేటివ్ కామన్స్ వేదికను సృష్టించిన ఈ 26 ఏండ్ల ఉద్యమకారుడు వేధింపులను, భారీ శిక్ష తప్పించుకోవడానికి ఆత్మహత్య చేసుకున్నాడు. విజ్ఞానానికి సంకెళ్ళు వేయడం మాత్రమే కాదు, డిజిటల్ సాంకేతిక పరిజ్ఞానం ద్వారా- చాటింగ్, షాపింగ్ మొదలుకొని మనిషి ప్రతి కదలికను నమోదు చేసి నిరంతర నిఘా వేసేందుకు అమెరికాలో రంగం సిద్ధమవుతున్నది. ఈ ప్రయోగం ఇవాళ కాకుంటే రేపు ప్రపంచ వ్యాప్తంగా ప్రభుత్వాలు అమలు చేస్తాయనడంలో సందేహం లేదు. నెట్ సమానత్వాన్ని కోరడంతో సరిపోదు. నెట్ ద్వారా నిరంకుశ రాజ్య స్థాపన జరగకుండా అడ్డుకోవడానికి కూడా ప్రజలు సంసిద్ధులు కావాలె.

know about Earthquakes

• An earthquake is a result of a sudden release of energy in the earth’s crust that creates seismic waves

• Earthquakes are recorded with a seismograph and are reported on a magnitude on the Richter scale.

• In general, earthquakes of magnitude less than 3 are imperceptible, and more than 7 cause serious damage

• The intensity of an earthquake can also be measured on the Modified Mercalli (MM) scale. The MM scale quantifies the effect an earthquake has on humans, natural objects and man-made structures

• The shaking caused by earthquakes can result in landslides, and in volcanic activity as well. When a large earthquake occurs in the oceans, the ocean floor can suffer sufficient displacement to cause a tsunami

• Earthquakes are usually caused by rupture of geological faults, but can also be caused by volcanic activity, landslides, mine blasts and nuclear experiments

• The point of initial rupture of an earthquake is called its hypocentre, while the point on the surface directly above it is called the epicentre

• Earthquakes that occur under the ocean and of high magnitude can generate tsunamis (eg 2004 Indian Ocean tsunami)

• The most powerful earthquake ever recorded is the Valdivia earthquake in Chile in 1960. It measured 9.5 on the Richter scale
  

Mechanism of action

• Earthquakes can occur anywhere within the earth where there is stored elastic energy sufficient enough to drive fault propagation along a fault plane

• Tectonic plates move past each other smoothly only if there are no irregularities and asperities. Most plate boundaries do have asperities and this leads to stick-slip behaviour

• Once the boundary has locked into a relative stable position, continued relative motion between the plates leads to increased stress and stored strain energy

• This continues until the stress rises sufficiently to break through the relative stable position, suddenly sliding over the locked position of the fault and thereby releasing the stored energy

• The energy is released as a combination of elastic seismic waves, frictional heating of the surface and cracking of rock, thereby causing an earthquake

• This process of gradual build up of stress and sudden release of energy in the form of earthquakes is called elastic-rebound theory

• It is estimated that less than 10 % of the total energy of an earthquake is radiated as seismic energy. Most of the earthquake’s energy is used to power fracture growth or is converted as heat generated by friction
  

Occurrence of earthquakes

• Minor earthquakes occur nearly constantly. Most of these happen in places like California and Alaska in the US, as well as in Guatemala, Chile, Peru, Indonesia, Iran, Pakistan, Turkey, Greece, Italy, Japan and New Zealand. Larger earthquakes occur less frequently

• However, in general, earthquakes can occur almost anywhere (even away from plate boundaries)

• The relationship between frequency and intensity of earthquakes is roughly exponential i.e. for instance, there are roughly 10 times as many earthquakes of magnitude 4 as of magnitude 5

• Most of the world’s earthquakes occur in Pacific Ring of Fire seismic belt. Massive earthquakes occur along other plate boundaries too, such as the Himalayas

Induced seismicity

• While most earthquakes occur due to natural movement of the earth’s tectonic plates, human activity can produce earthquakes as well

• Four main human activities that contribute to earthquakes include
• Large dams
• Drilling and injecting liquids into wells
• Coal mining
• Oil drilling
• For instance, the 2008 Sichuan earthquake in China is believed to have been caused by the Zipingpu dam which caused the pressure of a nearby fault to fluctuate, increasing the movement of the fault and the magnitude of the earthquake

Earthquakes and volcanic activity

• Earthquakes often occur in volcanic areas

• They are caused both by tectonic faults and the movement of magma in volcanoes

• Such earthquakes can serve as early warning of impending volcanic eruptions. Eg: Mount St Helens eruption of 1980 (USA)
  

Seismic waves

• Seismic waves are waves of force that travel through the earth

• 
  Earthquakes produces different types of seismic waves that travel through the earth at different velocities:
  
  
• P waves (Pressure or Primary waves): they are longitudinal waves that travel fastest through solids, and are therefore the first waves to appear on a seismogram
• S waves (shear or secondary waves): transverse waves that travel slower than P waves.
  
  
  They do not exist in fluids such as air or water
  
  
• Surface waves (Rayleigh waves and Love waves): slower than P and S waves, but have much larger amplitude. These surface waves cause most damage during an earthquake
• The propagation velocity of the seismic waves depends on density and elasticity of the medium

• In solid rock, P waves travel at about 6-7 km/s (within the mantle about 13 km/s), while S waves travel at about 2-3 km/s (mantle 9 km/s)

• Earthquakes can be recorded at great distances, since seismic waves travel through the whole of the earth’s interior

• The absolute magnitude of a quake is reported on the Moment Magnitude scale, while perceived magnitude is reported on the Modified Mercalli (MM) scale. The Richter scale is another scale that measures the absolute magnitude – it is no longer used in academic circles but is still used in popular parlance.

• As a rule of thumb, the distance to the earthquake epicentre is the number of seconds between the P and S waves multiplied by 8

What is an earthquake and what causes them to happen?

An earthquake is caused by a sudden slip on a fault. Stresses in the earth's outer layer push the sides of the fault together. Stress builds up and the rocks slips suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake. An earthquake occurs when plates grind and scrape against each other.

What is a fault?

Faults are fractures in Earth's crust where rocks on either side of the crack have slid past each other. Sometimes the cracks are tiny, as thin as hair, with barely noticeable movement between the rock layers. But faults can also be hundreds of miles long.

At what depth do earthquakes occur?

Earthquakes occur in the crust or upper mantle, which ranges from the earth's surface to about 800 kilometers deep (about 500 miles).

What is "surface rupture" in an earthquake?

Surface rupture occurs when movement on a fault deep within the earth breaks through to the surface. Not all earthquakes result in surface rupture.

How are earthquakes measured?

The familiar Richter scale (which is not a physical device but rather a mathematical formula) is no longer widely used by scientists to report an earthquake's size. Today, an earthquake's size is typically reported simply by its magnitude, which is a measure of the size of the earthquake's source, where the ground began shaking. While there are many modern scales used to calculate the magnitude, the most common is the moment magnitude, which allows for more precise measurements of large earthquakes than the Richter scale. A network of geological monitoring stations, each with instruments that measure how much the ground shakes over time called seismographs allow scientists to calculate an earthquake's time, location and magnitude. Seismographs record a zigzag trace that shows how the ground shakes beneath the instrument. Sensitive seismographs, which greatly magnify these ground motions, can detect strong earthquakes from sources anywhere in the world.

How are quakes classified?

Based on their magnitude, quakes are assigned to a class. An increase in one number, say from 5.5 to 6.5, means that a quake's magnitude is 10 times as great. The classes are as follows:

Great: Magnitude is greater than or equal to 8.0. A magnitude-8.0 earthquake is capable of tremendous damage.

Major: Magnitude in the rage of 7.0 to 7.9. A magnitude-7.0 earthquake is a major earthquake that is capable of widespread, heavy damage.

Strong: Magnitude in the rage of 6.0 to 6.9. A magnitude-6.0 quake can cause severe damage.

Moderate: Magnitude in the rage of 5.0 to 5.9. A magnitude-5.0 quake can cause considerable damage.

Light: Magnitude in the rage of 4.0 to 4.9. A magnitude-4.0 quake is capable of moderate damage.

Minor: Magnitude in the rage of 3.0 to 3.9.

Micro: Magnitude less than-3.0. Quakes between 2.5 and 3.0 are the smallest generally felt by people.

After an earthquake strikes, its magnitude is continuously revised as time passes and more stations report their seismic readings. Several days can pass before a final number is agreed upon.

What are the seismic zones of India?

The Geological Survey of India (GSI.) first published the seismic zoning map of the country in the year 1935. With numerous modifications made afterwards, this map was initially based on the amount of damage suffered by the different regions of India because of earthquakes. Color coded in different shades of the color red, this map shows the four distinct seismic zones of India. Following are the varied seismic zones of the nation, which are prominently shown in the map:

Zone - II: This is said to be the least active seismic zone

Zone - III: It is included in the moderate seismic zone

Zone - IV: This is considered to be the high seismic zone

Zone - V: It is the highest seismic zone

Earthquakes in India
Date	Location	Magnitude	Fatalities
Jun 16, 1819	Gujarat, India Fatalities 2,000
Jun 12, 1897	Assam, India	M 8.3	Fatalities 1,500
Apr 4, 1905	Kangra, India	M 7.5	Fatalities 19,000
Jan 15, 1934	Bihar, India - Nepal	M 8.1	Fatalities 10,700
Aug 15, 1950	Assam - Tibet	M 8.6	Fatalities 1,526
Dec 10, 1967	Koyna, India	M 6.3	Fatalities 177
Aug 20, 1988	Nepal - India border region	M 6.8	Fatalities 1,000
Oct 19, 1991	Northern India	M 6.8	Fatalities 2,000
Sep 29, 1993	Latur - Killari, India	M 6.2	Fatalities 9,748
May 21, 1997	Jabalpur, India	M 5.8	Fatalities 38
Jan 26, 2001	Gujarat, India	M 7.6	Fatalities 20,023
Jul 24, 2005	Nicobar Islands, India Region	M 7.2
Aug 10, 2009	Andaman Islands, India region	M 7.5

Nepal earthquake: Hundreds die, many feared trapped

Nearly 1,000 are known to have died in a powerful earthquake in Nepal, with many more feared trapped under rubble, officials say.

The 7.8 magnitude quake struck an area between the capital, Kathmandu, and the city of Pokhara, the US Geological Survey said.

Tremors were felt across the region, with further loss of life in India, Bangladesh, Tibet and on Mount Everest.

The government has declared a state of emergency in the affected areas.

A national police spokesman told the BBC that 970 people had died in the quake, and that more than 1,700 had been injured. At least 539 people were killed in the Kathmandu valley, he added.

Nepali Information Minister Minendra Rijal said there had been "massive damage" at the epicentre, from where little information is emerging.

Get the latest updates on the Nepalese earthquake

"We need support from the various international agencies which are more knowledgeable and equipped to handle the kind of emergency we face now," he said.

The US is sending a disaster response team to Nepal and has released an initial $1m (£0.7m) to address immediate needs, the US aid agency USAid has said.

Rescuers are digging through the rubble of collapsed buildings in the capital trying to reach survivors, as thousands prepare to spend the night outside as darkness fell.

A number of historic buildings have been destroyed.

Among those wrecked was the landmark Dharahara tower, with many feared trapped in its ruins.

After the earthquake struck, frightened residents came out into the streets. Mobile phones and other communications have been disrupted.

Kathmandu's landmark Dharahara tower before and after the earthquake

Analysis: Navin Singh Khadka, BBC News

Major historic monuments in the Nepalese capital have been destroyed in the powerful earthquake, eyewitnesses and officials have said.

These include a nine-storey tower, temples and some parts of what was once a royal palace, all listed as Unesco world heritage sites.

Pictures posted on social media show some of the monuments have been reduced to rubble.

Eyewitnesses say several others now have cracks and could collapse.

Officials have said some temples and monuments at other world heritage sites near Kathmandu have also been damaged.

These sites are Nepal's major tourist attractions.

Nepal had lost several such monuments during a major earthquake in 1934.

Quake levels Nepal landmarks

There are also reports of damage to Kathmandu airport which could hamper relief operations.

With little known about the extent of the damage around the earthquake's epicentre, there are fears the death toll could rise.

Rescuers are searching through rubble for survivors

Historic landmarks were wrecked in the earthquake

Aftershocks continued to ripple through the region hours later.

The quake triggered an avalanche on Mount Everest, killing at least eight people, and another five in Tibet, officials and reports say.

"Running for life from my tent. Unhurt. Many many people up the mountain," tweetedmountaineer Alex Gavan.

World's deadliest recent earthquakes

• Iran, 2003: More than 26,000 people killed in 6.6 earthquake near the city of Bam
• Indonesia, 2004: Devastating 9.1 earthquake and ensuing tsunami off the Sumatran province of Aceh kills more than 230,000 people in a dozen countries
• Pakistani-administered Kashmir, 2005: 7.6 earthquake near Muzafferabad kills about 100,000 people
• China, 2008: Nearly 90,000 killed in 7.9 earthquake in eastern Sichuan province
• Haiti, 2010: More than 220,000 people killed in 7.0 magnitude earthquake

At least 35 people have been killed in India, Indian officials say, with one death also reported in Bangladesh.

Indian Prime Minister Narendra Modi has met his ministers to review the situation. Pakistan's Prime Minister, Nawaz Sharif, has pledged help for the Nepalese authorities.

It is the worst earthquake to strike Nepal since one in 1934 all but destroyed Kathmandu.

There are fears the death toll could rise once the scale of the devastation becomes clear

This was the scene at Nepal's international airport

There has also been damage, and casualties, in India