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Lanka’s southern waters hide a gravity anomaly that baffles scientists

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1 year ago

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The Earth beneath your feet is far from still. While we understand quite a bit about the Earth’s surface, the interior remains a mystery. (CREDIT: International Centre for Global Earth Models / Wikimedia, CC BY 4.0)

One of the most puzzling phenomena lies beneath the Indian Ocean, south of Sri Lanka, where a massive gravity anomaly known as the Indian Ocean Geoid Low (IOGL) has confounded researchers for decades, said a report published by The Brighter Side News.

It said that this anomaly, marked by a dramatic 106-meter drop in the ocean’s surface, is the lowest geoid anomaly on Earth. Its origin remains a mystery, making it one of the most intriguing unresolved problems in Earth sciences. “The existence of the Indian Ocean Geoid Low is one of the most outstanding problems in Earth Sciences,” says Prof. Attreyee Ghosh, an assistant professor at the Centre for Earth Sciences, Indian Institute of Science, Bangalore.

It said: The ground beneath you may seem stable, but the Earth is in a state of constant motion. While we have a solid understanding of the Earth’s surface, its interior remains largely unexplored. Even with all our technological advancements, we still haven’t developed probes capable of reaching the Earth’s crust, which is just 35 kilometers deep. To uncover the mysteries of the Earth’s core and mantle, we rely on indirect methods.

Though the Earth may look like a perfect blue sphere from space, it’s actually more like a lumpy, misshapen potato. This uneven shape is due to the non-uniform distribution of matter inside the planet, which creates variations in gravity. The movement of tectonic plates, which form mountains and valleys, also contributes to these deformations.

Oceans cover 71% of the Earth’s surface, so these irregularities also affect the shape of the ocean. Without tides and currents, the ocean water would settle into a smooth, wave-like form called a geoid. This geoid rises in areas where gravity is strong and sinks where gravity is weak. These variations in the ocean’s surface, known as “geoid anomalies,” are caused by the distribution of mass deep within the Earth.

One of the most intriguing geoid anomalies is located south of Sri Lanka. Known as the Indian Ocean Geoid Low (IOGL), this massive area is characterized by a significant drop in gravity, causing the ocean surface to dip 106 meters. This “gravity hole” has puzzled scientists for decades.

In a recent study published in Geophysical Research Letters, Prof. Ghosh and her colleagues, along with researchers from the GFZ German Research Centre for Geosciences, investigated the missing mass causing the geoid low.

Past studies attributed it to a remnant of an ancient plate that dived into the mantle beneath another plate millions of years ago, but there had been no convincing explanation until now.

Using numerical models of mantle convection, the researchers explained the mass deficit. Mantle convection involves movement within the Earth’s mantle, where hotter, lighter material rises, and cooler, denser material sinks due to gravity. This movement was driven by seismic tomography models, which use seismic waves to create a 3-dimensional picture of the Earth’s interior.

The researchers discovered that ‘low-density anomalies’—the presence of lighter materials in the upper to mid-mantle beneath the IOGL—caused the gravity low in this region. Mantle plumes, or rising abnormally hot rock, can result in low-density anomalies.

However, no known mantle plume exists beneath the IOGL. Instead, they found hot material rising from the African large low-shear-velocity province (LLSVP) or the African superplume, near the IOGL, which gets deflected eastward and terminates beneath the IOGL. The deflection is possibly due to the fast motion of the Indian plate.

The researchers used supercomputers to simulate how the area could have formed, going as far back as 140 million years. “The Earth is basically a lumpy potato,” said Ghosh. “Technically, it’s not a sphere, but what we call an ellipsoid, because as the planet rotates, the middle part bulges outward.”

To find a potential answer, Ghosh and her colleagues used computer models to set the clock back 140 million years in order to see the big picture, geologically. “We have some information and some confidence about what the Earth looked like back then,” she said. “The continents and the oceans were in very different places, and the density structure was also very different.”

From that starting point, the team ran 19 simulations up to the present day, recreating the shifting of tectonic plates and the behaviour of magma inside the mantle. In six scenarios, a geoid low similar to the one in the Indian Ocean formed. The distinguishing factor in all six models was the presence of plumes of magma around the geoid low, believed to be responsible for the formation of the “gravity hole.”

The plumes themselves originated from the disappearance of an ancient ocean as India’s landmass drifted and eventually collided with Asia tens of millions of years ago. “India was in a very different place 140 million years ago, and there was an ocean between the Indian plate and Asia. India started moving north and as it did, the ocean disappeared, and the gap with Asia closed,” Ghosh explained.

As the oceanic plate went down inside the mantle, it could have spurred the formation of the plumes, bringing low-density material closer to Earth’s surface.

“A geoid low or a negative geoid anomaly would be caused by a mass deficit within the deep mantle. Our study explains this low with hotter, lighter material stretching from a depth of 300 km up to ~900 km in the northern Indian Ocean, most likely stemming from the African superplume,” says Prof. Ghosh.


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Indonesian Navy Sailing Ship KRI BIMA SUCI – 945 concludes official goodwill visit to Sri Lanka

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2026/04/19

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The Indonesian Navy Sailing Ship KRI BIMA SUCI – 945 departed the island on 18 Apr 2026, marking the successful completion of her official goodwill visit.

The ship was accorded a formal farewell by the Sri Lanka Navy in accordance with naval traditions at the Port of Colombo.

The visit also served as a valuable educational platform, as officer under-trainees and other personnel of the Sri Lanka Navy had the opportunity to conduct an observational
tour of the sailing vessel. This exchange of knowledge was complemented by a series of events designed to foster professional and social bonds.

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Heat Index at Caution Level in the Northern, North-central, North-western, Western, Sabaragamuwa, Eastern and Southern provinces and in Monaragala district

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11 hours ago

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2026/04/19

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Warm Weather Advisory
Issued by the Natural Hazards Early Warning Centre
Issued at 3.30 p.m. on 18 April 2026, valid for 19 April 2026

The Heat index, the temperature felt on human body is likely to increase up to ‘Caution level’ at some places in the Northern, North-central, North-western, Western, Sabaragamuwa, Eastern
and Southern provinces and in Monaragala district.

The Heat Index Forecast is calculated by using relative humidity and maximum temperature and this is the condition that is felt on your body. This is not the forecast of maximum temperature. It is generated by the Department of Meteorology for the next day period and prepared by using global numerical weather prediction model data.


Effect of the heat index on human body is mentioned in the above table and it is prepared on the advice of the Ministry of Health and Indigenous Medical Services.

ACTION REQUIRED
Job sites: Stay hydrated and takes breaks in the shade as often as possible.
Indoors: Check up on the elderly and the sick.
Vehicles: Never leave children unattended.
Outdoors: Limit strenuous outdoor activities, find shade and stay hydrated.
Dress: Wear lightweight and white or light-colored clothing.

Note:
In addition, please refer to advisories issued by the Disaster Preparedness & Response Division, Ministry of Health in this regard as well. For further clarifications please contact 011-7446491.

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‘Agents of the devil’ seeking to block Easter probe, Cardinal warns

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11 hours ago

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2026/04/19

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Warning that “agents of the devil who wish to hide the truth behind a wall of political posturing” were attempting to obstruct investigations into the Easter Sunday terror attacks, the Catholic Church has called for intensified public support and prayer to ensure justice for victims.

In a message issued ahead of the seventh anniversary of the April 21, 2019 bombings, Colombo Archbishop Cardinal Malcolm Ranjith said there were ongoing efforts by various forces to derail credible inquiries into the coordinated attacks that claimed 278 lives and left nearly 500 injured.

The statement noted that many of those killed had been attending Easter Sunday Mass when suicide bombers struck churches, including St. Anthony’s Shrine, Kochchikade, St. Sebastian’s Church, Katuwapitiya, and Zion Church, Batticaloa, causing widespread devastation and long-term suffering among survivors.

Seven years on, the Caridnal said, critical questions remain unanswered, including who masterminded the attacks, their motives, and why places of worship were targeted on Christianity’s most sacred day.

Full text of Cardinal Malcolm Ranjith’s message: On 21st April 2026, the Church in Sri Lanka will be commemorating the 7th Anniversary of the Easter Sunday bomb blasts, which killed 278 of our fellow human beings and brethren in the faith in the most brutal fashion. Most of these people had come to our Churches for Easter Sunday Masses and prayer services. Many families were rendered destitute. Nearly 500 people were injured and some of them carry life long disabilities, suffering from the after effects of these blasts. St. Anthony’s Church Kochchikade and St. Sebastian’s Church Katuwapitiya of the Catholic community and the Zion Church in Batticaloa were, quasi totally destroyed. The economy of the country suffered immensely with untold problems affecting many families, ever since then. However much we try to console the families of these victims, it is something that we humans are unable to achieve as only the Lord can truly console them.

Besides, we still do not know who murdered these people and caused so much of suffering to many others, and why and for what purpose they chose our Churches on a day that was most sacred to us to organize these attacks. After repeated pleas by the Catholic Church, now at last, the incumbent government and the security establishment, seem to be holding a credible inquiry into this episode of mass murder in order to find out who was really behind it.

And there are many forces actively seeking to obstruct these inquiries and divert the direction of the inquiry in an aimless fashion in order to hide the truth behind these attacks. They are nothing but the agents of the devil who wish to hide the truth behind a wall of political posturing. We need to storm Heaven and ask the Lord to strengthen the hands of the investigators to find out what really happened and who was behind this mass murder as well as why it was done to innocent people who had nothing to do with politics.

Hence, I call upon all of you to kindly storm Heaven with your prayers calling upon the Lord to help us find out what really happened that most tragic day. And so, I am declaring Sunday, the 19th of April 2026, as a special day of prayer for this purpose. I shall be most grateful to every one of you, beloved brethren, if you could recite special prayers in all the parishes of the Archdiocese at Sunday Mass on that day and offer prayers at home too for the success of these investigations. The special prayer for truth and justice for the victims of the bomb attacks, already approved by the Catholic Bishops’ Conference, could also be recited. I call upon all our Catholic devotees to join us in this effort.

Let us stand together firmly behind the efforts to find out the truth. Let us not be deceived by attempts of different people to hide the truth or divert attention in all kinds of directions in order to confuse the public.

May the Blessed Mother, our Lady of Lanka, intercede for us in this most important matter.

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