Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Most changes in Earth’s shape are due to changes in climate


Scientists using NASA satellite data found the shape of the Earth appears to be influenced by big climate events that cause changes in the mass of water stored in oceans, continents and atmosphere.

The study’s principal researchers are Minkang Cheng and Byron D. Tapley, of the Center for Space Research, University of Texas at Austin. They reviewed climate events like El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) that affect the amount of water moving in the oceans, atmosphere and continents.

The study shows significant variations in the shape of the Earth, defined by the Earth’s gravity field, or geoid, during the past 28 years might be partially linked to climate events. The study examined Earth’s oblateness, how much its rounded shape flattens at the poles and widens at the equator. Scientists measured the distance from ground stations to satellites by using Satellite Laser Ranging (SLR) data that are accurate within one millimeter.

The data reflected mass changes as water redistributed in oceans, atmosphere, and in soil. The redistribution resulted in slight changes of the Earth’s gravity field, detectable with geodetic satellites, those that study of the size and shape of the Earth.

The researchers found over the past 28 years, two large variations in the Earth’s oblateness were connected to strong ENSO events. Variations in mass distribution, which caused the change in the gravity field, were predominantly over the continents, with a smaller contribution due to changes over the ocean. The cause of a variation in the Earth’s mass over the 21-year period between 1978 and 2001, however, still remains a mystery.

The scientists also found that another change in mass distribution may have started in late 2002, which coincides with the moderate El Niño that developed at that time. "The main idea, however, is that the Earth’s large scale transport of mass is related to the long-term global climate changes," said Cheng. Cheng and Tapley’s research relied on NASA’s SLR data to measure changes in the longest wavelengths of the Earth’s gravity field in order to see how the global-scale mass was redistributed around the world.

The Earth’s gravity is an invisible force of attraction that pulls masses together. The relative motion of a small lighter object, such as a spacecraft, to a large heavy object such as the Earth, depends on how much mass each object has and how that mass is distributed. Scientists can measure the changes in Earth’s gravitational pull using instruments on the ground to track satellites in space. So, water mass shifts on Earth and the changes in shape of the Earth can be detected.

The long-term history of the SLR measurements make it possible for scientists to see the changes over time in melting glaciers and polar ice sheets and the associated sea level change. The SLR data have also been used to detect the motion of global tectonic plates on which landmasses rest, the deformation of the Earth’s crusts near plate boundaries, and the orientation and rate of spin of the Earth.

In March 2002, NASA and the German Aerospace Center launched the Gravity Recovery and Climate Experiment (GRACE) to sense small-scale variations in Earth’s gravitational pull from local changes in Earth’s mass. GRACE data will assist with future studies similar to Cheng and Tapley’s research. The GRACE satellite, together with 18 other NASA research satellites, have opened new windows to exploring Earth and to understanding the intricate processes that support life.

The study was published in a recent issue of the Journal of Geophysical Research-Solid Earth.

Rob Gutro | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union

nachricht UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>