Geologically justified maritime boundary

Published : 21 July 2014, 12:32 PM
Updated : 21 July 2014, 12:32 PM

The UN's Permanent Court of Arbitration (UN PCA) based in Hague, the Netherlands, recently delivered its judgment on delimitation of maritime boundary between India and Bangladesh. The verdict is not reversible or appealable. However, since the issuance of the verdict, both the international and domestic news and press media have been discussing and publishing the merit and demerits of the outcome. While the government of Bangladesh claims that they have "won" the sea battle with both Myanmar and India, many others disagree. The purpose of this article is to illustrate the geologic link between the land and ocean, and what factors should have been highlighted by both parties in settling this issue to avoid future conflicts between India and Bangladesh.

The Himalayan Mountains, Ganges-Brahmaputra-Meghna River Basins, Bengal Delta, Swatch of no Ground, and the Bengal Fan are all connected by geological processes that affect each other in a way that does not conform to political boundaries. Yet in managing the natural resources in a region that are bisected by political boundary requires some understanding of the processes that govern their existence and ecological balance. The sediments eroded in the Himalayas are carried by numerous rivers and deposited in the floodplains and coastal plain to form the Bengal Delta, of which both Bangladesh and Pashchimbanga are parts. More than half of one billion tons of annually transported sediments are carried by tides, waves, and ocean currents to the Bay of Bengal through the submarine canyon called "the Swatch of no Ground", which in turn form the world's largest submarine fan called the Bengal Fan. The majority of the sediments that feed the Swatch of no Ground flows through the rivers in Bangladesh, namely, the Ganges and its distributaries, Brahmaputra, and the Meghna. In fact, the Swatch of no Ground is a drowned river valley–most likely of the Passur River or the Meghna River – that existed during the last Ice Age about 12,000 years B.P. In this regard, the Swatch of no Ground is the most prominent geologic feature that separate the origin and the pathways of the sediments that form the country Bangladesh and parts of Indian states that lie to the western side of the Swatch of no Ground. The image below marks the location of the Swatch of no Ground and the blue arrow indicates the possible past connection of this feature to rivers originating in coastal areas of Bangladesh. Two green arrows are added by the author to show the general directions of "silt lines" in the nearshore zone of Bangladesh and Pashchimbanga. It is obvious that all distributaries of the Ganges funnel part of the sediment load to the Swatch of no Ground.

The submarine landforms are connected to the land through geologic processes, including upliftment of mountains, erosion of sediments, transport of sediments by rivers, deposition of sediments both on land and ocean floor. Consequently, the delimitation of maritime boundaries needs to take that land-ocean connection in making decisions.

As per the news report, the UN PCA took into account the concept of land-ocean connections in their verdict by extending the delimitation line from Hariabhanga and Raimangal estuary in a southerly direction, following the "silt line." However, they did not draw the entire boundary following this principle of "silt line". It is not clear if Bangladesh placed any documentation in support of this argument, or if even they pleaded for such settlement. Bangladesh certainly has a legitimate right on the sediments that are carried by the rivers that flow through it. Several geological studies have established the nexus between riverine sediments and the formation of huge (over 3,000,000 km2) submarine Bengal Fan. As per the UN PCA's judgment, most of the Swatch of no Ground along with the Bengal Fan belongs to India (shown by yellow arrows in the map above). This can be considered as a colossal loss on Bangladesh's part. In addition, the maritime boundaries among Myanmar, Bangladesh, and India have left Bangladesh as a sea-locked country.

On the other hand, if Bangladesh decides to build a cross dam across the head of the Swatch of no Ground in an attempt to reclaim coastal land by blocking the riverine sediments then it will have the potential to deprive the Bengal Fan of the sediments, which may leave India unhappy. Moreover, the prevailing easterly coastal current along the shoreline in Bangladesh will likely carry ocean pollution from Bangladesh's continental shelf to that of Indian side across the Swatch of no Ground. All of these potential disputes could be avoided by drawing the maritime boundary between India and Bangladesh following the existing natural boundary that separates these two countries, namely the Swatch of no Ground, as shown by red arrows in the map above. Although the maritime boundary is not drawn based on natural and geologic feature, namely the Swatch of no Ground, but in the future this may lead to conflicts between these two neighbors. Humans cannot defy the nature, but can minimise conflicts by living in harmony with the nature. The sooner we bow to the force and power of the nature, the better is will be for the humanity, as well as for the environment.

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Md. Khalequzzaman is a Professor of Geology at Lock Haven University, USA.