Express News Service
pole shiftEARTH TILTING? GROUNDWATER EXTRACTION IS A VILLAINImagine a sphere rotating, and the content of it is removed gradually. What happens to the sphere? The axis on which it is rotating tilts. This is exactly what has happened to Earth. Scientists have estimated that at least 2,150 gigatons of groundwater — equalling six millimetres of sea level rise — being pumped out of the earth and redistributed, has caused the planet’s axis to marginally tilt by 80 centimetres eastwards. This tilt has not occurred overnight.
It has gradually tilted between 1993 and 2010. This is a new area of research led by Seoul National University. The effects of groundwater extraction on the Earth’s tilt was first discovered only in 2016, and the latest research modelled the observed tilt in Earth’s rotational pole and the movement of water. Initially, the research had only focussed on glacial and ice sheet melt, but later expanded its study sphere to groundwater extraction, too.
The researchers have found that in particular, it is the groundwater extraction in mid-latitudes that is having a more profound impact on causing the tilt, and they zeroed in on areas in Northwestern India and North America. The groundwater pumping is now being considered as one more factor to sea level rise, basically shifting of a mass from one region to another which is causing a ‘wobble effect’, but without us actually feeling it. For the size of the earth, 80 cm is just a minuscule fraction. The researchers say that it is not a concern of Earth going topsy-turvy because even normally the rotational pole does change by a few metres in a year. But this research specifically studies the contribution of groundwater extraction and redistribution and how much that has played a role in the tilt. That amounts to 80 cm. The researchers say this tilt does not risk a shift in seasons but does impact the climate.
turbulenceTHREAT TO AIR TAXIS IN CITY: GUSTS OF WINDNew rules are being drafted by various countries, especially Europe and the USA, to facilitate air taxi services. Indian cities, too, are not far behind, although they have to catch up. However, while all that is happening in the background, aerial vehicles for services in the city — including transporting commuters from one location to another — are now being red-flagged. There there is a warning issued from research conducted by RMIT University’s Uncrewed Aircraft Systems (UAS) Research Team in Australia that flying within city limits could pose a grave danger to the aerial vehicles from gusts of wind that could throw the flying vehicle off course, posing risks to people in them, on the ground, as well as to standing structures and buildings.
The threat is that of sudden wind gusts around city buildings and urban infrastructure. Several studies, including RMIT’s, have measured how these sudden gusts of wind can destabilise aerial vehicles, and researchers have insisted that this aspect needs to be addressed by all globally before allowing such flights to operate within the city. The problem especially plagues the low-flying aerial vehicles because they take off at low speeds, like drones, and the sudden gusts can affect their flight path within a second of them being airborne, posing a threat to those around.
They have suggested that instead of low-speed take-offs, these aerial vehicles should be modified in such a way that they need more space for high-speed take-offs that could prevent them from being impacted by these sudden gusts of wind. The sudden gusts of wind in an urban domain, the researchers say, are because of the shapes of the building and the gaps between them which cause the wind drafts to be sharper and more forceful. Research is continuing on this front, wherein they are exploring different building shapes to minimise the adverse impacts on intra-city flights. They are also studying the sensitivity of vehicles to gusts and turbulence, as well as flight-stability technologies.
pole shift
EARTH TILTING? GROUNDWATER EXTRACTION IS A VILLAIN
Imagine a sphere rotating, and the content of it is removed gradually. What happens to the sphere? The axis on which it is rotating tilts. This is exactly what has happened to Earth. Scientists have estimated that at least 2,150 gigatons of groundwater — equalling six millimetres of sea level rise — being pumped out of the earth and redistributed, has caused the planet’s axis to marginally tilt by 80 centimetres eastwards. This tilt has not occurred overnight.
It has gradually tilted between 1993 and 2010. This is a new area of research led by Seoul National University. The effects of groundwater extraction on the Earth’s tilt was first discovered only in 2016, and the latest research modelled the observed tilt in Earth’s rotational pole and the movement of water. Initially, the research had only focussed on glacial and ice sheet melt, but later expanded its study sphere to groundwater extraction, too.
The researchers have found that in particular, it is the groundwater extraction in mid-latitudes that is having a more profound impact on causing the tilt, and they zeroed in on areas in Northwestern India and North America. The groundwater pumping is now being considered as one more factor to sea level rise, basically shifting of a mass from one region to another which is causing a ‘wobble effect’, but without us actually feeling it. For the size of the earth, 80 cm is just a minuscule fraction. The researchers say that it is not a concern of Earth going topsy-turvy because even normally the rotational pole does change by a few metres in a year. But this research specifically studies the contribution of groundwater extraction and redistribution and how much that has played a role in the tilt. That amounts to 80 cm. The researchers say this tilt does not risk a shift in seasons but does impact the climate. googletag.cmd.push(function() {googletag.display(‘div-gpt-ad-8052921-2’); });
turbulence
THREAT TO AIR TAXIS IN CITY: GUSTS OF WIND
New rules are being drafted by various countries, especially Europe and the USA, to facilitate air taxi services. Indian cities, too, are not far behind, although they have to catch up. However, while all that is happening in the background, aerial vehicles for services in the city — including transporting commuters from one location to another — are now being red-flagged. There there is a warning issued from research conducted by RMIT University’s Uncrewed Aircraft Systems (UAS) Research Team in Australia that flying within city limits could pose a grave danger to the aerial vehicles from gusts of wind that could throw the flying vehicle off course, posing risks to people in them, on the ground, as well as to standing structures and buildings.
The threat is that of sudden wind gusts around city buildings and urban infrastructure. Several studies, including RMIT’s, have measured how these sudden gusts of wind can destabilise aerial vehicles, and researchers have insisted that this aspect needs to be addressed by all globally before allowing such flights to operate within the city. The problem especially plagues the low-flying aerial vehicles because they take off at low speeds, like drones, and the sudden gusts can affect their flight path within a second of them being airborne, posing a threat to those around.
They have suggested that instead of low-speed take-offs, these aerial vehicles should be modified in such a way that they need more space for high-speed take-offs that could prevent them from being impacted by these sudden gusts of wind. The sudden gusts of wind in an urban domain, the researchers say, are because of the shapes of the building and the gaps between them which cause the wind drafts to be sharper and more forceful. Research is continuing on this front, wherein they are exploring different building shapes to minimise the adverse impacts on intra-city flights. They are also studying the sensitivity of vehicles to gusts and turbulence, as well as flight-stability technologies.
