The Restless Sea

Dominion, Volume 27, Issue 111, 3 February 1934, Page 20

The Restless Sea

(By

J. Drummond, F.L.S., F.Z.S.,

for “The Dominion.”)

THE sea has played an important pari in New Zealand's geological history. Several times it has completely submerged the country. By taking a large block of land, it now separates New Zealand by 1200 miles of water from the Australian continent, of which Old New Zealand was a part, leaving it a group of islands. Former connection with the continent stamps New’ Zealand as a continental island group, distinguished from oceanic islands, or were built up on coral reefs. For these reasons the sea and its power and importance in the world closely interest all who concern themselves with New Zealand’s present and past affairs. The sea’s golden age was in the Cretaceous Period, the Age of Chalk Deep calling to deep, it advanced, and the land trembled. All low-lying lands, and all valleys near the continents’ edges were swallowed up. These words are figurative. The advance was not sudden or tumultuous. Flowing and ebbing, and gaining continually, the sea seemed to feel that there was eternity in which to complete its victory. The recession of the waters that marked later epochs was not contemplated. Famous marine reptiles, whose remains rest in rocks in New Zealand and in many other parts, reached their greatest development in Cretaceous seas. Most of them became extinct about the time that the Cretaceous Period ended. Then, and later, there stretched across a large part of the world the vastest inland sea of which there are any traces. Extending east from the Atlantic through the Mediterranean Basin, it covered the whole of Southern Europe and Northern Africa. The sun shone on it in Asia Minor. Arabia, Persia, Baluchistan, the Himalayan area, and Further India. It girdled half the globe. Sway of battle between laud and water changing, the Himalayas, the Caucasus and the mountains of Persia. Arabia and Asia Minor usurped the eastern half of the Central Sea. The Carpal bums, the Apennines, the Swiss Alps and the Pyrenees arose near its northern shores It was broken up into disconnected inland seas and into salt water lakes. As Ihe water continued to retreat, the Central Sea gradually shrank. The

Mediterranean Sea is all that remains of its glory. The Central Sea is a convenient title for that expanse of water. Professor E. Suess, an Austrian geologist, gave it a more classical title, Tethys, the name of the consort of Oceanus, ruler of the oceans. In a general way, but rashly even then no doubt, estimates have been made of the sea’s age. It is usually placed at about’loo,ooo,ooo years. More accurate is the estimated area it occupies, 113,000,000 square miles. The area of the land is 54,000,000 square miles. The sea’s average depth is 12,500 ft.; the average height of the land is 2000 ft. The sea’s greatest depth in a trough called the Nero Deep, 150 miles south-east of Tokio, Japan, is 32,630 ft.. that is, more than six miles and a quarter; the highest peak of the land, Mount Everest, 29,1-11 ft., could be drowned in the Nero Deep. If Mount Cook. Mount Tasman and Mount Egmont stood ou the floor of the Nero Deep, one on top of the other, the highest peak would be about 530 ft. below the surface of the water. A deep is an ocean depth greater than 18,000 ft. There are fifty-seven deeps, all measured and named. Most of them arc in the Pacific Ocean. The pastures of the sea are rich, richer than the pastures .if the laud, supporting huge sharks, groat whales and countless smaller creatures. The late Prince of Monaco, a noted student of oceanology, scientist first, prince afterwards, brought up the Jiving creature that holds the record for the greatest depth. It was a fish and it lived 19,506 ft.. three miles and threequarters, beneath the surface of the North Atlantic. Mr. A. 11. Clark, an American oceanologist, has given in a single paragraph an account of some of (he conditions in the deeps: “The temperature of the water declines as the depth increases. It declines rapidly at first, then more slowly. In the abysses it is mostly a few degrees above freezing point. The pressure increases. The light gradually fades. At about 650f1. in the clearest and most sunlit seas there is only a pale moonlight at noon on the brightest day Al greater depths there is no light whatever. Wave motion dies away, amt not far below the surface there is perpetual quiet even in the liercesi hurricane.”