598 



NATURE 



{Oct. 17, 1889 



GEOGRAPHICAL NOTES. 



Dr. Mohn contributes to the Scottish Geographical Afagazine 

 a useful summary of our knowledge of the Barents Sea, between 

 Spitzbergen and Novaya Zemlya. The depths of the Barents 

 Sea contrast in a marked degree with those of the Norwegian 

 and Greenland Seas. Between Jan Mayen and Norway, and 

 between Greenland and Spitzbergen, there are depths of upwards 

 of 2000 fathoms, but the bottom of the Barents Sea is found at 

 depths under 300 fathoms. The transition from the great depths 

 in the western part of the Northern Ocean to the shallows of the 

 Barents Sea is marked by an imaginary line drawn between 

 Western Spitzbergen and Tromso. Here is a submarine plateau, 

 having on its western wall a steep declivity towards the depths 

 of the Northern Ocean, and on its eastern wall a relatively flit 

 sea-bottom rising slowly towards the coasts of Norway, Russia, 

 Novaya Zemlya, and Spitzbergen, and continuinjj towards the 

 north-east, with only 100 fathoms of water, to between Spitz- 

 bergen and Novaya Zemlya. The adjacent Siberian Sea is also 

 characterized by slight depths. The Barents Sea is therefore 

 deepest in its western part. A depreesion of upwards of 200 

 fathoms in depth projects from here into the middle of the sea 

 eastwards as far as the longitude of Vardo, the part of the 

 bottom lying further east having depths varying between 200 

 and 100 fathoms, but more generally averaging the latter. The 

 l(X)-fathom line runs very near the Norwegian coast ; here the 

 bottom consequently descends rather quickly from the coast-line. 

 But from Kola, on the Murman coast, the lOO-fathom line 

 stretches direct to Novaya Ze nlya, and continues in a sinuous 

 direction to the north of this twin island. P\irther on we find it 

 again in higher latitudes. It incloses Bear Island, and reaches 

 the banks of Western Spitzbergen. On the eastern plain of the 

 Barents Sea, where the depths are mostly a little over 100 

 fathoms, are found some slight elevations and depressions ; the 

 form of the sea-bottom is slightly undulating. As regards the 

 material deposited on the bottom of the Barents Sea, we have 

 acquired some knowledge from the researches of the Norwegian 

 North Atlantic Expedition. The specimens consist of a peculiar 

 sort of clay, different in description from that lying on the 

 bottom of the deep Northern Ooean. Its chief constituent is 

 silica (quartz) ; it is very poor in carbonate of lime, and is cha- 

 racterized by the existence in it of the shells of a small animal 

 .belonging to the Foraminifera, from which our zoologists have 

 given it the name of the Rhabdammina clay. Its colour is dark 

 green. It is probable that this material is derived froja the 

 quartz rocks of the surrounding countries, which, by means of 

 the rivers, tides, currents, and drift-ice, have been spread over 

 the sea-bottom. The salinity of the water of Barents Sea is 

 slightly lower than that of the Norwegian Sea, particularly at 

 the surface. The temperature of the water in the Barents Sea 

 exhibits some contrast in its southern and its northern part. The 



mean annual temperature of the surface is 5° C. at the North 

 Cape, 4° on the Murman coast, from 2° to 1° C. on the west coast 

 of Novaya Zemlya, and 1° C. at Bear Island. In the month of 

 August — the warmest for surface temperatures — the normal 

 temperature of the sea is 9° C. at Soioen (Hammerfest), 8° to 

 6° and lower on the Mum an coast, 5° to 1° at Novaya Zemlya, 

 2° at Bear Island, and 1° at the South Cape of Spitzbergen. In 

 March — the coldest month for surface temperatures — the tempera- 

 ture^of the sea is 2° "4 C. at the North Cape, i°-4 at Vardo, 0° to 

 - 2° at Novaya Zemlya, a little above 0° at Bear Island, 

 and 1° at the South Cape of Spitzbergen. For the whole year 

 as well as for the warmest and the coldest months, the surface 

 water is consequently warmest at the coast of Finmarken, and 

 coldest in the sea between Novaya Zemlya and Spitzbergen. At 

 the depth of 100 fathoms we have 4° C. off Hammerfest, 3° off 

 the Tana Fjord, 2° off the Fisher Peninsula (Rybatschi Ostrow), 

 1° off Kola, and 0° along a line running south to north from the 

 70lh to the 75th parallels of latitude, and east to west along the 

 last-named parallel. Similar curves show the other isotherms 

 for 1° to 4°. In the above-named bay, bordered by the 200- 

 fathom line, are found temperatures of from 1° to 3° above zero. 

 At the sea-bottom, irrespective of its depth, the temperature 

 is distributed in the following degrees. Off and near the coast 

 of Finmarken it is upwardsof 4° from Vardo to off Hammerfest, 

 and 5° further west. From here the temperature decreases 

 towards the east and towards the north. The current runs in 

 the Barents Sea as a rule along the coast of Finmarken and the 

 Murman coast eastwards, in the eastern part of the sea north- 

 wards, and in the northern part, between Novaya Zemlya and 

 Spitzbergen, westward. Along the east coast of Spitzbergen 

 the current sets southwards. The warm Atlantic current, a 

 branch of the Gulf Stream (this name being taken in its widest 

 sense) runs along the coast of Finmarken, curves on leaving 

 the Murman coast towards the north, and turns then to the west 

 towards Bear Island. It fills the sea down to the bottom with 

 its temperate water. This is warmest in the southern branch 

 running eastwards ; and it becomes by and by, further on, cooled 

 down by the neighbouring ice-cold water with which it mixes, 

 and which from the northern regions is driven southwards and 

 westwards. The surface of the sea between Spitzbergen and 

 Novaya Zemlya is always covered with drifting ice. The larger 

 animals in the sea being the objects of capture, live on smaller 

 animals. The development and presence of these small organ- 

 isms is greatly dependent on the temperature of the v ater. But 

 their presence in a certain place, and to a certain time, depends 

 upon the oceanic currents, these being as a rule so strong, and 

 the locomotive powers of the small animals so small, that these 

 must follow the movements of the currents. The animals living 

 at or on the bottom get their food brought to them by means of 

 the currents. 



Dr. Julius Roll, of Darmstadt, in the course of a mission 

 of botanical exploration in the north-west of America, made an 

 ascent in June 1888 of a summit in the Cascade Mountains, 

 hitherto unnamed on our maps. The peak in question is situated 

 under long. 121° 15' W., and lat. 47° 22' N., between two small 

 lakes, and about 20 miles north of Easton on the Northern 

 Pacific Railroad. The following is taken from a short account 

 of his excursion contributed by Dr. Roll to the current number 

 of Petermann^ s Mitteihmgen. On June 19, in company with 

 Herr Purpus, he made his way through the primeval forest, anc' 

 o ver rising ground to the foot of the mountain, pitching his ter 

 at an altitude of 5500 feet. The next morning the actua 

 summit was ascended. It is composed of melaphyr, and mar 

 pieces of agate and rock crystal were found. The steep slop^ 

 are overgrown with ceanothus bushes, maples, and pine 

 between which bloom yellowish-red lilies {Liliutn philadek 

 phicum), and species of dark-red pentstemons. Three successi\ 

 summits were climbed. The highest was estimated at 7500 feet] 

 unfortunately the exact altitude could not be ascertained, as tl; 

 traveller's barometer had become useless. The rocky crest 

 the mountain is covered with the Selaginelli rupestris, pentste 

 mons, phlox, pedicularis, several saxifrages, and some loy 

 umbelliferous plants, &c. Traces of bears, mooses, and mouD 

 tain sheep were observed. The following day another ascefl 

 was made, and a magnificent view of the snow-covered Mout 

 Tacoma obtained. Some weeks later, finding that the peak 

 had ascended was unnamed, Dr. Roll designated it "MouB 

 Rigi," from the resemblance to the Swiss mountain of tha 

 name. 



