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Recent earth tremors around Victoria dam – a scientific explanation in relation to the tectonic history of Sri Lanka

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By Dulip Jayawardena

(Retired Economic Affairs Officer United Nations ESCAP 1990 to 2003 Former Director Geological Survey Department- Present GSMB (1983-1986)

Earth tremors were reported in the print and electronic media on 29 August and also 2 September 2020 in an area surrounding the Victoria dam in Kandy. The Geological Survey and Mines Bureau (GSMB) the designated Agency to monitor such earth tremors have mobilized geologists to investigate the damages caused by such earth movements.

The Director General of the GSMB announced that there had been no records of such tremors in the Pallekelle seismic monitoring station which is close to the areas affected. However, a senior Director who is a geologist gave a different version and reported that tremors were detected at the monitoring station.

The reporting of earth tremors and earthquakes are on the Richter scale, which has been revised many times. According to this scale unit 1 records a micro tremor not felt or felt rarely and the frequency of occurrence worldwide is several million per year. The scale 2 -2.9 is felt slightly by some people and damage to buildings and the worldwide frequency per year is over 1 million. The magnitude 3 to 3.9 is a minor tremor often felt by people but very rarely causes damage. Shaking of indoor objects can be noticed. The frequency is over 100,000 per year. The magnitude 4.0 -4.9 is noticeable with the shaking of indoor objects and ratting noises and felt by most people in the affected area and slightly felt outside and generally causes minimal damage. Moderate to significant damage very unlikely. Some objects may fall off shelves or be knocked over and the frequency worldwide is 10,000 15 000 per year.

 

Tectonic evolution of Sri Lanka theories of three peneplains and upliftment and plate tectonics

The earlier theory of the three peneplains was proposed by Wadia in the late 1948 when he was the Director of the Mineralogy Department. His theory was based on the ring of waterfalls around the country that were caused by erosion of the rocks to the upper plain mid plain and the lower plain.

However, in 1974 after a gravity survey was conducted by the Geological Survey Department (Present GSMB ) covering the entire island and it was conclusively proved that the there was an upliftment of the Precambrian terrain composed of over 80 per cent of the land area which had earlier being recognized as the Highland and Vijayan Series.

The Gravity Map of Sri Lanka on the scale of 1:100000 was published with an explanation as Professional Paper No 3 with T Hatherton, D. B. Pattiarachchi and V. V. C. Ranasinghe. This was possible with technical cooperation by the Government of New Zealand under the Colombo Plan.

During the gravity survey, earlier trigonometrical stations established by the Survey Department on the triangular survey for the topographical maps were reopened. It was then noticed that some bench marks for these stations were uplifted especially in the hill country of the island.

The most significant revelation was a significant gravity low continuously identified between the eastern boundary of the Highland and Vijayan series rocks. This led to the theory of plate tectonics where the Vijayan series sank below the Highland series forming a convergent plate boundary.

The evidence for such activity can be seen in the change of course of the Mahaweli river from a direction of north east to north as indicated by some Buddhist shrines such as Somawathi and Deegawapi which were earlier on the banks of this river.

Earth tremors are noted frequently along this fault line and geologists together with geophysicists should constantly monitor such movements.

 

A new tectonic plate boundary between

Australia and India

Many researchers have carried out extensive studies on the development of a new tectonic plate boundary in the Indian Ocean which occurred over 40 million years ago. This boundary that runs east west is about 400-500 kms south of Sri Lanka. If this boundary is activated it will have devastating effects to the infrastructure south of Sri Lanka such as the Hambantota Port, Mattala Airport and industrial zones envisaged in the area.

 

Danger to Victoria concrete arch

dam from earth tremors

Victoria dam is the largest concrete dam in Sri Lanka built under the Mahaweli Project costing Rs 9.8 billion during 1980-1984 to solve problems as hydropower for the country diversion of water for agriculture, solving unemployment, encouraging inland fisheries and flood control.

“Victoria Dam is a double curvature (cupola) arch dam of 122 meters maximum height and 520 meters crest length. The arch dam is constructed with the individual crown cantilevers. A large amount of water load acting on the upstream surface of the dam is transferred to the abutment by arch action and a certain amount of water load is transferred to the foundation by cantilever action. The destruction of the Victoria dam can cause flooding up to Trincomalee affecting the livelihood of the area .crack was identified and it has been developing in the downstream face of the Victoria dam (Sri Lanka Head works Division of Mahaweli Authority 2014)Therefore the Victoria Dam is investigated to identify the effect of earthquake ” (Ref Assessment of Concrete Arch dam under Possible Earthquake Loading in Sri Lanka Case Study on Victoria Dam by Shobitha Tharamarajah and Kamal Karunananda International Journal of Scientific and Engineering Research Volume 8 Issue 10 October 2017 ISSN 2229-5518)”

Another article titled “Comprehensive monitoring of Victoria Dam /Civil + Structural Engineer magazine <https://csengineermag.com/comprehensive-monitoring-of- victor…. > should also be studied.

All interested parties should access these excellent articles as it covers all aspects of strengthening the Victoria dam to avoid any major catastrophe.

 

Reservoir induced earthquakes –application to arch and gravity dams in Sri Lanka

As stated above, the only large concrete arch dam in Sri Lanka is the Victoria dam, which was built mainly for the supply of hydroelectricity. Another concrete arch dam is Canyon producing hydroelectricity.

Apart from the Victoria dam there are dams built for irrigation and hydroelectricity throughout Sri Lanka which are gravity concrete dams. There are also embankment dams constructed mainly for irrigation.

The gravity dams constructed mainly for generation of hydroelectricity are at Bowatenna, Broadlands, Castlereigh Dyraaba, Kalu Ganga, Kotmale, Kukule Ganga,Laksapana, Maskeliya, Moragahakanda, Moragolla Norton ,Nilambe, Polgolla Puhulpola, Rantambe, and Upper Kotmale Ganga,

(Ref Dams and reservoirs of Sri lanka –Wikipedia< https://en.wikipedia.org/wiki/List_of _dams_and reservoirs_in _…)

It is asked whether the gravity dams constructed mainly in the hill country are being monitored for any tremors using the latest seismic equipment as at Victoria as reservoirs of these dams will also be subject to reservoir triggered seismicity giving rise to earth tremors or earthquakes.

It is also noted that most of the above reservoirs are located in areas with less inhabitants and the tremors will not be felt as at Victoria.

Dams in Sri Lanka are built on valleys that have formed by active erosion with recent theory of upliftment as indicated by the gravity survey covering the island. It is also known that under compressional tectonic force reverse or thrust faults produce upliftment giving rise to tremors

It is known that reservoir induced seismicity can also occur after a few years and will depend on the permeability of the rocks beneath the reservoir.

It is also noted that indused earthquakes at reservoirs experience delayed triggering at depths of 10 to 20 kilometers. Such earthquakes may occur 10 to twenty years after filling the reservoir. In this regard it is noted that the Victoria reservoir was filled in 1985 which is 35 years ago.

Further the other gravity dams also should be subject to regular monitoring for any tremors due to reservoir triggered seismicity. However, it is not easy to predict reservoir induced seismicity due to the state of stress and the rock strength at earthquake depths are not subject to direct measurement.

Ref : Dams and earthquakes –Seismology Research Centre

(https://www.src.com.au/earthquakes/seismology-101/dams-eart .. )

 

Recommendations

In the above article I have attempted to explain the recent earth tremors experienced in the valley surrounding the Victoria Dam as well as the high ground which occupied by villagers. These tremors were felt on two occasions and the GSMB has mobilized a number of geologists to investigate what damages have been caused to the dwellings etc. A retired Professor of Geology of the Peradeniya University has attributed the tremors to the extensive quarrying operations carried out for limestone in an area above the Victoria dam.

The GSMB is also investigating the triggering of these tremors due to the Victoria reservoir indused seismicity which I have also dealt above.

With my past experience as a geologist who mapped the area in the late 1970s there are many fold belts with prominent fault zones that could be activated with gradual upliftment of the terrain as proved by the gravity survey conducted in 1975.

It is important to monitor the other gravity dams I have listed as with age of these dams the pore pressure will increase at depths to kilometers beneath the reservoir.

I urge the government to appoint a multidisciplinary team of experts comprising of geologists , geophysicists, hydrologists, civil engineers and those from the NBRO as well as the universities to study the state of the Victoria dam as well as other gravity dams and recommend an effective method of monitoring such tremors.

I had been involved in advising the late Dr A. N. S. Kulasinghe on the problems involved in the construction of the Upper Kothmale gravity dam in a landslide prone area. However it is now opportune to monitor any seismicity and take remediable measures.

As revealed above the Victoria dam developed a crack on the downstream part in 2014 and is important that constant monitoring should be carried out .

I was also involved in following up the construction of the Victoria dam in early 1980 when the then Professor of Geology of the Peradeniya University revealed that a major fault zone runs along the axis of the dam. However, the consultant engineers responded that the Victoria dam was designed to take a wave crest of 10 meters over the dam and there is no danger to its stability.

I hope this article will be helpful to the experts to draw up a comprehensive long term plan to monitor our gravity dams that mainly generate hydroelectricity as well provide water for irrigation.

Last but not least the effects of climate change on these reservoirs and the surrounding areas should not be ignored .

(The author can be reached at fasttrack@eol.lk )



Features

Cyclones, greed and philosophy for a new world order

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Floods caused by Cyclone Ditwah in Sri Lanka

Further to my earlier letter titled, “Psychology of Greed and Philosophy for a New World Order” (The Island 26.11.2025) it may not be far-fetched to say that the cause of the devastating cyclones that hit Sri Lanka and Indonesia last week could be traced back to human greed. Cyclones of this magnitude are said to be unusual in the equatorial region but, according to experts, the raised sea surface temperatures created the conditions for their occurrence. This is directly due to global warming which is caused by excessive emission of Greenhouse gases due to burning of fossil fuels and other activities. These activities cannot be brought under control as the rich, greedy Western powers do not want to abide by the terms and conditions agreed upon at the Paris Agreement of 2015, as was seen at the COP30 meeting in Brazil recently. Is there hope for third world countries? This is why the Global South must develop a New World Order. For this purpose, the proposed contentment/sufficiency philosophy based on morals like dhana, seela, bhavana, may provide the necessary foundation.

Further, such a philosophy need not be parochial and isolationist. It may not be  necessary to adopt systems that existed in the past that suited the times but develop a system that would be practical and also pragmatic in the context of the modern world.

It must be reiterated that without controlling the force of collective greed the present destructive socioeconomic system cannot be changed. Hence the need for a philosophy that incorporates the means of controlling greed. Dhana, seela, bhavana may suit Sri Lanka and most of the East which, as mentioned in my earlier letter, share a similar philosophical heritage. The rest of the world also may have to adopt a contentment / sufficiency philosophy with  strong and effective tenets that suit their culture, to bring under control the evil of greed. If not, there is no hope for the existence of the world. Global warming will destroy it with cyclones, forest fires, droughts, floods, crop failure and famine.

Leading economists had commented on the damaging effect of greed on the economy while philosophers, ancient as well as modern, had spoken about its degenerating influence on the inborn human morals. Ancient philosophers like Plato, Aristotle, and Epicurus all spoke about greed, viewing it as a destructive force that hindered a good life. They believed greed was rooted in personal immorality and prevented individuals from achieving true happiness by focusing on endless material accumulation rather than the limited wealth needed for natural needs.

Jeffry Sachs argues that greed is a destructive force that undermines social and environmental well-being, citing it as a major driver of climate change and economic inequality, referencing the ideas of Adam Smith, John Maynard Keynes, etc. Joseph Stiglitz, a Nobel Laureate economist, has criticised neoliberal ideology in similar terms.

In my earlier letter, I have discussed how contentment / sufficiency philosophy could effectively transform the socioeconomic system to one that prioritises collective well-being and sufficiency over rampant consumerism and greed, potentially leading to more sustainable economic models.

Obviously, these changes cannot be brought about without a change of attitude, morals and commitment of the rulers and the government. This cannot be achieved without a mass movement; people must realise the need for change. Such a movement would need  leadership. In this regard a critical responsibility lies with the educated middle class. It is they who must give leadership to the movement that would have the goal of getting rid of the evil of excessive greed. It is they who must educate the entire nation about the need for these changes.

The middle class would be the vanguard of change. It is the middle class that has the capacity to bring about change. It is the middle class that perform as a vibrant component of the society for political stability. It is the group which supplies political philosophy, ideology, movements, guidance and leaders for the rest of the society. The poor, who are the majority, need the political wisdom and leadership of the middle class.

Further, the middle class is the font of culture, creativity, literature, art and music. Thinkers, writers, artistes, musicians are fostered by the middle class. Cultural activity of the middle class could pervade down to the poor groups and have an effect on their cultural development as well. Similarly, education of a country depends on how educated the middle class is. It is the responsibility of the middle class to provide education to the poor people.

Most importantly, the morals of a society are imbued in the middle class and it is they who foster them. As morals are crucial in the battle against  greed, the middle class assume greater credentials to spearhead the movement against greed and bring in sustainable development and growth. Contentment sufficiency philosophy, based on morals, would form the strong foundation necessary for achieving the goal of a new world order. Thus, it is seen that the middle class is eminently suitable to be the vehicle that could adopt and disseminate a contentment/ sufficiency philosophy and lead the movement against the evil neo-liberal system that is destroying the world.

The Global South, which comprises the majority of the world’s poor, may have to realise, before it is too late, that it is they who are the most vulnerable to climate change though they may not be the greatest offenders who cause it. Yet, if they are to survive, they must get together and help each other to achieve self-sufficiency in the essential needs, like food, energy and medicine. Trade must not be via exploitative and weaponised currency but by means of a barter system, based on purchase power parity (PPP). The union of these countries could be an expansion of organisations,like BRICS, ASEAN, SCO, AU, etc., which already have the trade and financial arrangements though in a rudimentary state but with great potential, if only they could sort out their bilateral issues and work towards a Global South which is neither rich nor poor but sufficient, contented and safe, a lesson to the Global North. China, India and South Africa must play the lead role in this venture. They would need the support of a strong philosophy that has the capacity to fight the evil of greed, for they cannot achieve these goals if fettered by greed. The proposed contentment / sufficient philosophy would form a strong philosophical foundation for the Global South, to unite, fight greed and develop a new world order which, above all, will make it safe for life.

by Prof. N. A. de S. Amaratunga 
PHD, DSc, DLITT

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SINHARAJA: The Living Cathedral of Sri Lanka’s Rainforest Heritage

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Damp and thick undergrowth

When Senior biodiversity scientist Vimukthi Weeratunga speaks of Sinharaja, his voice carries the weight of four decades spent beneath its dripping emerald canopy. To him, Sri Lanka’s last great rainforest is not merely a protected area—it is “a cathedral of life,” a sanctuary where evolution whispers through every leaf, stream and shadow.

 “Sinharaja is the largest and most precious tropical rainforest we have,” Weeratunga said.

“Sixty to seventy percent of the plants and animals found here exist nowhere else on Earth. This forest is the heart of endemic biodiversity in Sri Lanka.”

A Magnet for the World’s Naturalists

Sinharaja’s allure lies not in charismatic megafauna but in the world of the small and extraordinary—tiny, jewel-toned frogs; iridescent butterflies; shy serpents; and canopy birds whose songs drift like threads of silver through the mist.

“You must walk slowly in Sinharaja,” Weeratunga smiled.

“Its beauty reveals itself only to those who are patient and observant.”

For global travellers fascinated by natural history, Sinharaja remains a top draw. Nearly 90% of nature-focused visitors to Sri Lanka place Sinharaja at the top of their itinerary, generating a deep economic pulse for surrounding communities.

A Forest Etched in History

Centuries before conservationists championed its cause, Sinharaja captured the imagination of explorers and scholars. British and Dutch botanists, venturing into the island’s interior from the 17th century onward, mapped streams, documented rare orchids, and penned some of the earliest scientific records of Sri Lanka’s natural heritage.

Smallest cat

These chronicles now form the backbone of our understanding of the island’s unique ecology.

The Great Forest War: Saving Sinharaja

But Sinharaja nearly vanished.

In the 1970s, the government—guided by a timber-driven development mindset—greenlit a Canadian-assisted logging project. Forests around Sinharaja fell first; then, the chainsaws approached the ancient core.

 “There was very little scientific data to counter the felling,” Weeratunga recalled.

“But people knew instinctively this was a national treasure.”

The public responded with one of the greatest environmental uprisings in Sri Lankan history. Conservation icons Thilo Hoffmann and Neluwe Gunananda Thera led a national movement. After seven tense years, the new government of 1977 halted the project.

What followed was a scientific renaissance. Leading researchers—including Prof. Savithri Gunathilake and Prof. Nimal Gunathilaka, Prof. Sarath Kottagama, and others—descended into the depths of Sinharaja, documenting every possible facet of its biodiversity.

Thilak

 “Those studies paved the way for Sinharaja to become Sri Lanka’s very first natural World Heritage Site,” Weeratunga noted proudly.

A Book Woven From 30 Years of Field Wisdom

For Weeratunga, Sinharaja is more than academic terrain—it is home. Since joining the Forest Department in 1985 as a young researcher, he has trekked, photographed, documented and celebrated its secrets.

Now, decades later, he joins Dr. Thilak Jayaratne, the late Dr. Janaka Gallangoda, and Nadika Hapuarachchi in producing, what he calls, the most comprehensive book ever written on Sinharaja.

 “This will be the first major publication on Sinharaja since the early 1980s,” he said.

“It covers ecology, history, flora, fauna—and includes rare photographs taken over nearly 30 years.”

Some images were captured after weeks of waiting. Others after years—like the mysterious mass-flowering episodes where clusters of forest giants bloom in synchrony, or the delicate jewels of the understory: tiny jumping spiders, elusive amphibians, and canopy dwellers glimpsed only once in a lifetime.

The book even includes underwater photography from Sinharaja’s crystal-clear streams—worlds unseen by most visitors.

A Tribute to a Departed Friend

Halfway through the project, tragedy struck: co-author Dr. Janaka Gallangoda passed away.

 “We stopped the project for a while,” Weeratunga said quietly.

“But Dr. Thilak Jayaratne reminded us that Janaka lived for this forest. So we completed the book in his memory. One of our authors now watches over Sinharaja from above.”

Jumping spide

An Invitation to the Public

A special exhibition, showcasing highlights from the book, will be held on 13–14 December, 2025, in Colombo.

“We cannot show Sinharaja in one gallery,” he laughed.

“But we can show a single drop of its beauty—enough to spark curiosity.”

A Forest That Must Endure

What makes the book special, he emphasises, is its accessibility.

“We wrote it in simple, clear language—no heavy jargon—so that everyone can understand why Sinharaja is irreplaceable,” Weeratunga said.

“If people know its value, they will protect it.”

To him, Sinharaja is more than a rainforest.

It is Sri Lanka’s living heritage.

A sanctuary of evolution.

A sacred, breathing cathedral that must endure for generations to come.

By Ifham Nizam

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How Knuckles was sold out

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Knuckles range

Leaked RTI Files Reveal Conflicting Approvals, Missing Assessments, and Silent Officials

“This Was Not Mismanagement — It Was a Structured Failure”— CEJ’s Dilena Pathragoda

An investigation, backed by newly released Right to Information (RTI) files, exposes a troubling sequence of events in which multiple state agencies appear to have enabled — or quietly tolerated — unauthorised road construction inside the Knuckles Conservation Forest, a UNESCO World Heritage site.

At the centre of the unfolding scandal is a trail of contradictory letters, unexplained delays, unsigned inspection reports, and sudden reversals by key government offices.

“What these documents show is not confusion or oversight. It is a structured failure,” said Dilena Pathragoda, Executive Director of the Centre for Environmental Justice (CEJ), who has been analysing the leaked records.

“Officials knew the legal requirements. They ignored them. They knew the ecological risks. They dismissed them. The evidence points to a deliberate weakening of safeguards meant to protect one of Sri Lanka’s most fragile ecosystems.”

A Paper Trail of Contradictions

RTI disclosures obtained by activists reveal:

Approvals issued before mandatory field inspections were carried out

Three departments claiming they “did not authorise” the same section of the road

A suspiciously backdated letter clearing a segment already under construction

Internal memos flagging “missing evaluation data” that were never addressed

“No-objection” notes do not hold any legal weight for work inside protected areas, experts say.

One senior officer’s signature appears on two letters with opposing conclusions, sent just three weeks apart — a discrepancy that has raised serious questions within the conservation community.

“This is the kind of documentation that usually surfaces only after damage is done,” Pathragoda said. “It shows a chain of administrative behaviour designed to delay scrutiny until the bulldozers moved in.”

The Silence of the Agencies

Perhaps, more alarming is the behaviour of the regulatory bodies.

Multiple departments — including those legally mandated to halt unauthorised work — acknowledged concerns in internal exchanges but issued no public warnings, took no enforcement action, and allowed machinery to continue operating.

“That silence is the real red flag,” Pathragoda noted.

“Silence is rarely accidental in cases like this. Silence protects someone.”

On the Ground: Damage Already Visible

Independent field teams report:

Fresh erosion scars on steep slopes

Sediment-laden water in downstream streams

Disturbed buffer zones

Workers claiming that they were instructed to “complete the section quickly”

Satellite images from the past two months show accelerated clearing around the contested route.

Environmental experts warn that once the hydrology of the Knuckles slopes is altered, the consequences could be irreversible.

CEJ: “Name Every Official Involved”

CEJ is preparing a formal complaint demanding a multi-agency investigation.

Pathragoda insists that responsibility must be traced along the entire chain — from field officers to approving authorities.

“Every signature, every omission, every backdated approval must be examined,” she said.

“If laws were violated, then prosecutions must follow. Not warnings. Not transfers. Prosecutions.”

A Scandal Still Unfolding

More RTI documents are expected to come out next week, including internal audits and communication logs that could deepen the crisis for several agencies.

As the paper trail widens, one thing is increasingly clear: what happened in Knuckles is not an isolated act — it is an institutional failure, executed quietly, and revealed only because citizens insisted on answers.

by Ifham Nizam

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