oleh admin | Mar 24, 2025 | earth, earthquakes, geology, news, seismology
On Monday, an earthquake with a magnitude of 4.5 on the Richter scale hit Tibet, as reported by the National Center for Seismology (NCS), according to ANI news on March 24th.
As per the NCS, the quake happened at a relatively shallow depth of 5 kilometers, which makes the area prone to aftershocks.
Following a posting on X, NCS stated, “Magnitude EQ: 4.5, Time: March 24, 2025 at 10:08:35 IST, Latitude: 28.94 N, Longitude: 93.82 E, Depth: 5 km, Area: Tibet.”
On March 15, an earthquake with a magnitude of 3.5 shook Tibet earlier that day.
As per the National Centre for Seismology (NCS), the quake happened at a depth of 10 kilometers, which makes it prone to aftershocks.
The NCS stated in an X post that “On March 15, 2025 at 00:49:17 IST, an earthquake with a magnitude of 3.5 was recorded. The epicenter had coordinates latitude 28.39N and longitude 86.89E, with a depth of 10 kilometers, located in Tibet.”
On March 13, the National Center for Seismology reported that three earthquakes with magnitudes between 3.5 and 4.3 hit Tibet.
Shallow earthquakes pose a higher risk than deep ones because they unleash their considerable energy nearer to the Earth’s crust. Consequently, this leads to intensified ground vibrations and heightened destruction of buildings along with more significant loss of life when contrasted with deep quakes, which tend to dissipate force before reaching the surface.
The Tibetan Plateau experiences significant seismic activity because of colliding tectonic plates.
Tibet and Nepal sit along a significant geological fracture zone where the Indian tectonic plate collides with the Eurasian plate, leading to frequent seismic activity. This ongoing collision causes substantial uplifting forces capable of altering the elevations of the Himalayan summits, according to reports from Al Jazeera.
Marianne Karplus, a seismologist and geophysicist, stated to Al Jazeera that educating individuals about earthquakes and constructing quake-resistant buildings, along with providing funds for renovations and robust infrastructure, could safeguard people and properties during powerful seismic events.
“The Earth’s system is highly intricate, and forecasting earthquakes remains beyond our capabilities. Nonetheless, we can carry out scientific research to gain deeper insights into the factors triggering earthquakes in regions like Tibet and enhance our understanding of the tremors and their effects,” stated Karplus, a professor of geological sciences at the University of Texas at El Paso, during an interview with Al Jazeera. (ANI)
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oleh admin | Des 2, 2024 | earth, earth science, environment, science, venus
WASHINGTON – The Earth is essentially an oceanic planet, with approximately 71% of its surface submerged under water. Venus, our nearest celestial counterpart, is occasionally referred to as Earth’s sister due to similarities in mass and structure. Despite its current scorched and desolate landscape, could Venus have originally possessed vast bodies of water like ours?
According to recent findings, which estimated the water content within the planet’s inner layers—a crucial factor in determining if Venus ever possessed vast bodies of water—the answer is negative. These scientists determined that the planet’s core likely lacks significant moisture, aligning with theories suggesting Venus became extremely arid following an initial period where its exterior was primarily made up of molten material—magma—and since then has maintained a bone-dry landscape.
Water is deemed essential for sustaining life, hence the research indicates that Venus has never been inhabitable. The new evidence does not back up earlier theories suggesting that Venus might contain subsurface water reserves from a vanished ocean.
Volcanic activity, through the release of gases into a planet’s atmosphere, offers insights into the composition of terrestrial planets’ interiors. When magma moves upward from a deep internal zone known as the mantle towards the crust, it brings with it various substances originating from lower layers within the Earth.
On Earth, volcanic gases consist of over 60% water vapor, suggesting a water-abundant interior. In contrast, studies found that the gases from Venusian volcanoes contain at most 6% water vapor, pointing towards an extremely dry inner composition.
“We suggest that a habitable past would be associated with Venus’ present interior being water-rich, and a dry past with Venus’ present interior being dry,” said Tereza Constantinou, a doctoral student at the University of Cambridge’s Institute of Astronomy and lead author of the study published on Monday in the journal Nature Astronomy.
“Atmospheric chemistry indicates that volcanic eruptions on Venus emit minimal amounts of water, suggesting that the planet’s interior—the origin of these eruptions—is also largely devoid of moisture. This aligns with the idea that Venus has maintained a consistently arid surface for an extended period and was never hospitable,” Constantinou noted.
Venus is the planet that orbits as the second closest to the Sun, with Earth following as the third.
“There are two contrasting theories about water history on Venus: one suggests it maintained a mild climate for eons with bodies of surface water, whereas the alternative proposes that an initially scorching-hot Venus never managed to form any surface liquids,” as stated by Constantinou.
The diameter of Venus, approximately 7,500 miles (12,000 km), is slightly smaller than Earth’s, which measures around 7,900 miles (12,750 km).
“Venus and Earth are frequently referred to as sister planets due to their comparable mass, radius, density, and proximity to the Sun. Nevertheless, their developmental trajectories took very different directions,” Constantinou stated.
“Currently, Venus boasts surface conditions that are vastly different from those on Earth, characterized by an atmospheric pressure 90 times higher, surface temperatures reaching approximately 465°C (869°F), and a hazardous atmosphere filled with sulfuric acid clouds. These significant differences highlight the distinct difficulties involved in comprehending Venus beyond merely considering it as Earth’s twin,” stated Constantinou.
It seems the narrative was distinct on Mars, which is the fourth planet from the sun.
Mars shows signs of having once possessed vast oceans filled with liquid water billions of years back. In contrast, similar characteristics haven’t been observed on Venus. Research from August, which analyzed seismic information gathered by NASA’s automated InSight rover, suggests that Mars might contain a significant underground body of liquid water trapped beneath layers of fragmented volcanic rock. This accumulation could potentially flood the whole planet as one enormous sea.
Although Venus hasn’t received as much attention as Mars, upcoming missions aim to change this. In the 2030s, NASA’s proposed DAVINCI mission intends to study Venus thoroughly—from its atmosphere all the way to its surface—by employing both flybys and a descending probe. Similarly, during the same decade, the European Space Agency plans to launch their EnVision orbiter which will focus on conducting detailed radar imaging of Venus along with comprehensive atmospheric research.
“Venus serves as a natural lab for examining how conditions suitable for life—or the absence of them—develop,” stated Constantinou.
— Reuters
This article
Was there ever water on Venus? Scientists now know for sure.
was originally published in
GMA News Online
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oleh admin | Sep 2, 2024 | earth, earth science, engineering, geology, science
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Scientists identified a torus-like area at the upper boundary of the outer core.
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This less dense area aids in agitating the molten metal, thereby producing the magnetic field.
Researchers have discovered an enormous ring-like formation hidden deep below the surface.
Scientists from the Australian National University utilized seismic waves created by
earthquakes
to gaze into the Earth’s enigmatic liquid center.
By following the trajectory of these waves throughout the Earth, scientists discovered a layer approximately hundreds of kilometers deep where their speed decreased by two percent compared to usual.
The doughnut-shaped formation encircles the Earth’s liquid outer core along an equatorial path, potentially playing a key role in generating our planet’s shielding magnetic field.
Professor Hrvoje Tkalčić, who led the research, states: “The magnetic field is an essential component required for sustaining life on Earth’s surface.”
Our planet consists of four primary layers.
the exterior crust, the partly molten mantle, a fluid metallic outer core, and a solid metallic inner core.
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When the movement of tectonic plates in the crust creates earthquakes, these produce vibrations that spread out through all the other layers of the Earth.
Leveraging the global network of seismic monitoring stations,
Scientists can observe how the waves propagate and use this information to forecast the circumstances beneath the water’s surface.
Researchers typically focus on the large, strong wavefronts that circulate globally within the initial hour following an earthquake.
Nevertheless, Professor Tkalčić and his co-author Dr. Xiaolong Ma managed to identify this pattern by examining the subtle remnants of waves that persisted for several hours following the primary shock.
The technique demonstrated that seismic waves propagating close to the poles were traveling at a quicker pace compared to those nearer to the equator.
When they compared their findings with various models of the Earth’s interior, Professor Tkalčić and Dr Ma discovered that these observations were most accurately described by the existence of an extensive subterranean ‘torus’, essentially a doughnut-shaped area.
They forecast that this area is located solely at low latitudes and aligns with the equator close to the upper boundary of the outer core, where the liquid part interfaces with the mantle.
“We aren’t certain about the precise thickness of the doughnut, but we deduced that it extends several hundred kilometers below the core-mantle boundary,” states Professor Tkalčić.
Due to the vital importance of this area, their discovery might also hold significant consequences for understanding life on our planet and beyond.
The Earth’s outer core extends about 2,160 miles (3,480 km), which is somewhat bigger than the size of Mars.
Primarily composed of molten nickel and iron, convection currents combined with the planet’s spin drive the fluid metals in this region into elongated vertical whirls oriented from north to south, similar to colossal water tornadoes.
The rotating flows within these molten materials function akin to a dynamo, generating the Earth’s magnetic field.
As this donut-shaped area has risen to the upper part of the liquid outer core, it implies that it might contain an abundance of lighter elements such as silicon, sulfur, oxygen, hydrogen, or carbon.
Professor Tkalčić states: “Our discoveries are intriguing as this reduced speed within the liquid core suggests a significant presence of lightweight chemical elements in those areas, which would consequently decelerate the seismic waves.”
These lightweight components, along with variations in temperature, assist in agitating the fluid within the outer core.
Without that vigorous movement to power the planet’s internal dynamo, Earth’s magnetic field may not have come into existence.
In the absence of the magnetic field, the planet’s surface would face an unrelenting assault from charged particles.
From the sun, which has the power to damage the genetic material of living organisms.
This ring-like area could thus be an essential clue in understanding how life originated on Earth and what signs we should search for when identifying potentially livable exoplanets.
Dr. Tkalčić concludes: “Our findings might encourage further investigation into the magnetic fields of both our planet and others.”
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