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 Gas hydrate research: Advanced knowledge and new technologies
23.03.2018 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht New technologies and computing power to help strengthen population data
22.03.2018 | University of Southampton

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>