Free Republic

If you look at a map of Earth's gravity, you will see a huge blue spot south of India, indicating a region where gravity is weaker than average. This spot is called the Indian Ocean Geoid Low (IOGL), and it is the largest gravity anomaly on our planet.A gravity anomaly is a difference between the actual gravity measured at a location and the theoretical gravity expected for a perfectly smooth and spherical Earth. But Earth's gravity isn't perfectly uniform and variations in mass distribution beneath the surface cause fluctuations in gravitational pull.Gravity anomalies can be caused by variations in the...

Scientists have identified mysterious formations deep in Earth’s mantle, raising new questions about the planet’s interior. These strange shapes, often referred to as “blobs,” or “sunken worlds,” resemble ancient fragments of Earth’s mantle but appear in places where such material shouldn’t exist. The discovery, published recently in Scientific Reports, was made possible through a new imaging technique called full-waveform inversion. This method combines data from multiple seismographs into a single, detailed image of Earth’s interior. Unlike traditional seismic imaging, which stitches together data from individual earthquakes, this advanced approach provides a clearer picture of what lies beneath the surface. Use...

An international team of geophysicists using a new imaging technique that measures the speed of seismic waves caused by earthquakes to locate the juncture of tectonic plates in the Earth’s mantle say they have discovered the remnants of what appears to be a “lost world” beneath the Pacific Ocean. Previous methods to locate these junctures between tectonic plates have always found them where scientists expected them to be. However, this latest joint effort by geophysicists from ETH Zurich and the California Institute of Technology (Cal Tech) found indications of these zones at locations that display no indications of tectonic plates...

Using NASA’s InSight Mars lander, scientists have precisely measured Mars’ rotation, detecting a subtle acceleration and the planet’s wobble due to its molten core. This study offers unprecedented insights into the Martian core’s size and shape, providing vital information for understanding Mars’ internal structure. Credit: NASA/JPL-Caltech/UArizona. Data sent by the spacecraft before it retired last December has provided new details about how fast the planet rotates and how much it wobbles. Scientists have made the most precise measurements ever of Mars’ rotation, for the first time detecting how the planet wobbles due to the “sloshing” of its molten metal core....

Microscopic granules of sweet potato starch (kūmara) have been discovered with Asia-Pacific taro and Pacific yam (uwhi) at Triangle Flat, a site located on the northern tip of New Zealand's South Island, according to an RNZ report. Researchers from the University of Otago – Ōtākou Whakaihu Waka determined that the Māori cultivated these crops as early as A.D. 1290 to 1385. "The first people who came here, came here to garden as well as to hunt things and they demonstrated from the outset that they were really sophisticated gardeners and they continued to be sophisticated gardeners over time," said archaeologist...

Jupiter’s gravity field varies with depth, which indicated that material is flowing as far down as 3,000 km (1,864 mi). Combined with information obtained during previous perijoves, this latest data suggests that Jupiter’s core is small and poorly defined. This flies in the face of previous models of Jupiter, which held that the outer layers are gaseous while the interior ones are made up of metallic hydrogen and a rocky core. ... Another interesting find was that Jupiter’s gravity field varies with depth, which indicated that material is flowing as far down as 3,000 km (1,864 mi). Combined with information...

Scientists believe a slowing or reversing inner core could potentially affect Earth's magnetic field. At the center of the Earth lies a solid metal ball that rotates independently of our spinning planet. Scientists have debated the inner core's rotation speed and direction. However, new research points to the inner core varying speed in recent years. However, researchers are not exactly sure if there are any effects from the inner core slowing down or reversing. Danish seismologist Inge Lehmann discovered the ball-shaped inner core in 1936. The inner core is buried approximately 3,220 miles deep inside Earth. The solid metal ball...

...The heart of our planet has been spinning unusually slowly for the past 14 years, new research confirms. And if this mysterious trend continues, it could potentially lengthen Earth's days — though the effects would likely be imperceptible to us.Earth's inner core is a roughly moon-size chunk of solid iron and nickel that lies more than 3,000 miles (4,800 kilometers) below our feet. It is surrounded by the outer core — a superhot layer of molten metals similar to those in the inner core — which is surrounded by a more solid sea of molten rock, known as the mantle,...

The rotation of Earth's inner core really has slowed down, a new study has confirmed, opening up questions about what's happening in the center of the planet and how we might be affected. Led by a team from the University of Southern California (USC), the researchers behind the finding think this change in the core's rotation could change the length of our days – albeit only by a few fractions of a second, so you won't need to reset your watches just yet. "When I first saw the seismograms that hinted at this change, I was stumped," says Earth scientist...

A new study of metal ore deep inside the moon is offering fresh evidence that Earth's natural satellite was formed by an ancient planet crashing into Earth long ago. This long-theorized interplanetary collision — which scientists believe occurred some 4.5 billion years ago — saw a Mars-sized planet named 'Theia' slice itself into hot lava fragments upon impact with the Earth. While some of Theia's planetary remains appear to be buried as dense and massive 'blobs' deep underneath Africa and the Pacific Ocean's tectonic plates, scientists said evidence for where the rest of Theia went after this crash had remained...

The Moon’s contraction causes fault scarps and moonquakes in the south pole, posing risks for lunar outposts. Findings from a recently published paper led by Smithsonian senior scientist emeritus Thomas R. Watters reveal evidence that the south polar region of Earth’s moon has experienced the effects of the shrinking moon. Global contraction of the moon has caused young lobate thrust fault scarps near and within some regions NASA has proposed for the crewed Artemis III moon landing. The paper, “Tectonics and Seismicity of the Lunar South Polar Region,” published recently in the Planetary Science Journal, associates one of the most...

The first hints that the moon had an Earth-like interior came from NASA's Apollo missions. Data gathered by the lunar landers' instruments suggested that the celestial body was differentiated — or layered with denser material at the center and less dense material nearer the surface — as opposed to uniform rock all the way through. Apollo astronauts even left seismometers on the moon, which later revealed that it experiences moonquakes... However, scientists were only recently able to sort through the massive data sets from the Apollo missions and other lunar probes to get a clearer picture of the moon's insides....

Ice Age Magnetic Reversal Was Global Event And Linked With Super Volcano Eruption And Rapid Climate Variability, Says New Research October 17, 2012 in Geology & Climate During the last ice age, around 41,000 years ago, there was a very rapid and complete reversal of the Earth’s geomagnetic field, according to new research. There was already localized evidence of polarity reversals during this time, but with the new research, the theory that it was a global event is now strongly supported. And very interestingly, it is one that nearly coincided with the very fast, short-term climate variability of the last...

A study published Tuesday suggests that Earth has an additional inner core that may tell the tale of a “significant global event from the past.” The highly specialized study published in Nature found that there is a giant metal ball sitting within the Earth’s inner core, known as the innermost inner core (IMIC). The ball is roughly 800 miles, and has been part of geological theory for quite some time, but the results from the study almost conclusively prove its existence (since we can’t get down there and check with our own eyes). The study was conducted by a team...

NASA’s Artemis program took an important step forward this weekend, with CAPSTONE finally reaching its destination—a near-rectilinear halo orbit (NRHO) around the Moon. The 55-pound cubesat will now test this promising orbit in preparation for the Gateway lunar space station. CAPSTONE, short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, reached NRHO on Sunday, November 13, according to an Advanced Space press release. Later this week, the $33 million cubesat will attempt a pair of tiny clean-up maneuvers to confirm its placement in the lunar orbit. In addition to being the first human-built device to operate in NRHO,...

Mysterious Shift in Earth's Gravity Suggests Equator is Bulging By Robert Roy Britt Senior Science Writer posted: 02:00 pm ET 01 August 2002 Something strange has been going on under our feet for the past four years. Earth's gravity field suddenly shifted gears and began getting flatter, reversing a course of centuries during which the planet and its gravity field grew rounder each year. The scientists who noticed the change and report it in the Aug. 2 issue of the journal Science suspect Earth itself may be flattening out, with the oceans rising near the equator, but they aren't...

Satellites solve mystery of low gravity over Canada 20:16 10 May 2007 NewScientist.com news service Kelly Young The GRACE satellites have detected changes in the gravitational field over regions of Canada that can be attributed to the crust bouncing back after the melting of a glacier 20,000 years ago and convection in Earth's mantle (Illustration: Science/M Tamisiea) If it seems Canadians weigh less than their American neighbours, they do – but not for the reasons you might think. A large swath of Canada actually boasts lower gravity than its surroundings. Researchers have puzzled for years over whether this was due...

Rotating 3D view of Earth's blobs. (Cottaar & Lekic/Geophysical Journal International, 2016) ********************************************************************************************* Earth's interior is not a uniform stack of layers. Deep in its thick middle layer lie two colossal blobs of thermo-chemical material. To this day, scientists still don't know where both of these colossal structures came from or why they have such different heights, but a new set of geodynamic models has landed on a possible answer to the latter mystery. These hidden reservoirs are located on opposite sides of the world, and judging from the deep propagation of seismic waves, the blob under the African continent...

Earth is far from a solid mass of rock. The outer layer of our planet – known as the lithosphere – is made up of more than 20 tectonic plates; as these gargantuan slates glide about the face of the planet, we get the movement of continents, and interaction at the boundaries, not least of which is the rise and fall of entire mountain ranges and oceanic trenches. Yet there's some debate over what causes these giant slabs of rock to move around in the first place. Amongst the many hypotheses put forward over the centuries, convection currents generated by...

The researchers explain that instruments for measuring the strength of the Earth's magnetic field were first invented only approximately 200 years ago. In order to examine the history of the field during earlier periods, science is helped by archaeological and geological materials that recorded the properties of the field when they were heated to high temperatures. The magnetic information remains "frozen" (forever or until another heating event) within tiny crystals of ferromagnetic minerals, from which it can be extracted using a series of experiments in the magnetics laboratory. Basalt from volcanic eruptions or ceramics fired in a kiln are frequent...