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Reconstructing past deep-water circulations of Indian Ocean

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The global conveyor belt, shown in part here, circulates cool subsurface water and warm surface water throughout the world. The Atlantic Meridional Overturning Circulation is part of this complex system of global ocean currents.

Global overturning circulation — the equatorward transport of cold, deep waters and the poleward transport of warm, near-surface waters — controls ocean heat distribution and atmospheric carbon dioxide levels, thus playing a critical role in global climate, says a report published by The Hindu yesterday.

It said: Studies have indicated that tectonically driven changes in the ocean gateways such as the closure of the Central American Seaway, a body of water that once separated North America from South America, since the late Miocene period, had a dramatic impact on the circulation.

It is thought that tectonic changes might have led to the formation of two separate water bodies — northern component water in the North Atlantic and Antarctic Bottom Water (AABW) in the Southern Ocean. Consequently, it is also hypothesised that there would have been large-scale changes in the Deep Water Circulation (DWC) in the oceans across the world, thus impacting global climate through ocean-atmosphere carbon dioxide and heat exchanges.

But these formulations have remained untested due to lack of adequate data. Some records that are available are from near the deep-water formation regions mostly from the Pacific and the Atlantic Oceans. Hence, they might not necessarily reflect the impact and change in deep water circulation.

Now, the Indian Ocean does not have any major deep-water formations of its own. It acts only as a host for NCW and AABW. Further, the northern parts of the Indian Ocean are located at one of the terminal ends of the GOC, far away from the deep-water formation regions and oceanic seaways. These specific features could make the northern Indian Ocean an ideal basin to do this.

Few studies have been carried out in the Indian Ocean to reconstruct past deep water circulations based on iron-manganese crust records and authigenic neodymium isotope composition of sediment cores. But iron-manganese crusts are situated at deeper depths  and are bathed only by AABW, making it suitable only for the reconstruction of the history of AABW, and authigenic neodymium isotope records are available only from the Bay of Bengal region. But they too cannot help as the Himalayan rivers that empty into the Bay also bring in substantial amounts of Neodymium particulates.

A new study by a team of researchers from the Goa-based National Centre for Polar and Ocean Research and the School of Earth, Ocean and Atmospheric Sciences in Goa University has now sorted out the issue.

The scientists have generated an authigenic neodymium isotope record from the Arabian Sea and reconstructed the DWC record of the Indian Ocean for the period from 11.3 million years ago (Miocene era) to 1.98 million years ago (Pleistocene era).

“The record shows a clear shift from the Pacific water dominated deep circulation system before about nine million years ago, to the onset of a modern-like deep water circulation system in the Indian Ocean comprising of Antarctic bottom water and northern component water during the Miocene-Pliocene transition (about six million years ago). Our finding suggests a widespread impact of the late Miocene Central American Seaway closure on the evolution of ocean deep water circulation and validates the so-called Panama Closure Hypothesis,” says Dr. Waliur Rahaman from the National Centre for Polar and Ocean Research (NCPOR) and one of the corresponding authors.

The two months long expedition was carried out on-board drilling vessel R/V JOIDES Resolution from March 31 to May 31, 2015.

Commenting on the findings, Dr. Sambuddha Misra, Associate Professor, Centre for Earth Sciences, Indian Institute of Science, who was not part of the research work, says the study is highly significant since it provides unequivocal evidence in support of the theory that the closing of the gap between North and South America had led to the evolution of the modern form of GOC. The work is also commendable as it involved extremely difficult measurements, he adds.



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Teacher recruitment examinations will be conducted in accordance with the relevant court decisions – PM

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Prime Minister Dr. Harini Amarasuriya stated that the forthcoming two teacher recruitment examinations will be conducted in accordance with the relevant court decisions pertaining to the ongoing legal proceedings and further noted that, taking into consideration the requests received, steps have been taken to make a request to Court’s approval to revise the conditions of the effective date of degree completion.

The Prime Minister made these remarks while addressing a meeting held at Monaragala Royal College to brief education authorities of the Monaragala District on the new education reforms.

Under the new education reforms, Smart Boards will be provided to 132 schools in the Monaragala District as part of the program to equip secondary schools with modern technology. As a symbolic step under this initiative, Smart Boards were presented to 10 secondary schools under the Prime Minister’s patronage. This program is being implemented with the intervention of the Digital Task Force operating under the Prime Minister’s Office. It was also emphasized that a new digital policy, formulated with special attention to child protection, will be introduced in April.

As part of her visit to the Monaragala District on the 13 th of February, the Prime Minister observed the implementation of the new learning methodologies introduced for Grade One under the new education reforms. She visited Kumbukkana Sri Shanmugam Tamil Maha Vidyalaya and Maduruketiya Maha Vidyalaya in Monaragala to observe the educational activities of Grade One students.

Considering the increase of student numbers and the development of infrastructure facilities, the Prime Minister also approved a proposal submitted by the School Development Society to rename Maduruketiya Maha Vidyalaya as Monaragala Dharmaraja Maha Vidyalaya.

Teachers briefed the Prime Minister that the new education system, supported by revised workbooks and activity-based learning methods, has proven to be effective, with students participating enthusiastically.

Addressing education officials further at the meeting held at Monaragala Royal College, the Prime Minister stated:

“Although this will not provide a complete solution to the existing teacher vacancies, these examinations can offer considerable relief. According to the Court’s previous determination, the effective date of degree completion had been set as 30.06.2025. However, considering numerous requests and following the cabinet approval we have sought Court’s consent to revise this date. We will act in accordance with the decision granted.

Funds allocated for school infrastructure must be utilized transparently and in line with proper planning, and progress must be reported accordingly. We cannot move forward by dividing ourselves along national, provincial, rural, or urban lines. As education authorities, you must make swift and accurate decisions based on correct data.

Further, discussions are already underway within the Piriven Committee of the Ministry of Education to develop Piriven education and to address the issues faced by Piriven teachers.”

The event was attended by the members of the Maha Sangha, Uva Province Governor Attorney-at-Law Kapila Jayasekara, Deputy Minister of Trade and Commerce R.M. Jayawardhana, Member of Parliament Ajith Agalakada, Uva Provincial Education Secretary Nihal Gunarathne, and several officials from the education sector.

[Prime Minister’s Media Division]

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Low-pressure area is likely to form over the southeastern Bay of Bengal around 15th February

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Special Weather Bulletin issued by the Natural Hazards Early Warning Centre of the Department of Meteorology
Issued at 10.30 a.m. on 13 February 2026

A low-pressure area is likely to form over the southeastern Bay of Bengal around 15th February.

The general public are requested to be attentive to the future forecasts and bulletins issued by the Department of Meteorology in this regard

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Sajith points to irregularities in coal procurement deals

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Sajith

Opposition and Samagi Jana Balawegaya (SJB) Leader Sajith Premadasa has claimed that all five coal shipments, imported recently for the Lakvijaya Coal Power Plant, in Norochcholai, were of substandard quality.

The remarks were made on Thursday during a meeting of the Sectoral Oversight Committee on Infrastructure and Strategic Development at the Parliament complex, which summoned senior officials from the Ceylon Electricity Board (CEB), the Public Utilities Commission of Sri Lanka (PUCSL), and the Lanka Coal Company to discuss the controversial coal imports.

Premadasa raised concerns over the tender process, highlighting a lack of transparency and deviations from the original procurement plan for the country’s key 900-megawatt power plant. He noted that although the order for 2,500 tonnes of coal was issued in April, deliveries were delayed due to the May monsoon season.

The Opposition Leader criticised the shortened tender timeline, which was reduced from the standard 42 days to just 21, and demanded that reports approving the tender, technical instructions, and conditions for both previous and current coal tenders be submitted to Parliament.

Premadasa also questioned the qualifications and experience of the suppliers selected by the government, asking whether responsibility for the nation’s primary electricity production had been entrusted to an unsuitable company.

He also emphasised the coal specifications, stating that the net NCP value should be 5,900 and requested reports if the supplied coal failed to meet that standard. Premadasa asked whether coal had been added to boilers before test results were received, whether samples had been sent to India for testing, and requested the corresponding reports.

In addition, he sought clarity on potential financial losses exceeding one million rupees, reductions in the annual coal requirement due to extra coal burning, and any boiler damage caused by substandard coal.

The Opposition Leader called for a full investigation into the tender process, including a forensic audit, noting that prior questioning through the Sectoral Oversight Committee had already highlighted deficiencies in procurement procedures.

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