THE QUAKING EARTH.

Dominion, Volume 2, Issue 570, 27 July 1909, Page 6

THE QUAKING EARTH.

LECTURE BY PROFESSOR MARSHALL

:■ Professor .■T'.vMa : rshaU,"-'-M.'A. ) ' ; D.Sc..' : :;of 'Otago University.-College, addressed a large audience in the Municipal Concert : Hall last evening ,pn ithe , subject .oi "Volcanoes'' and'. Earthquakes."- /The lecture was' one. of .the 'series..^arranged :'' by the' City ' Council's Library: .Committee,/- and. Councillor, J. / E.' . Fitzgerald, presided.. : '.'' ; '''. •.'. ' ;.... V ;There.\was" no' portion: of the whole domain of .■geological" tlhought (said - the professor)' that: was the. subject.of so much misconcep-, .''iaon'.'ahd confusion of , thought as that /of' ; which;,'ho : 'Wa's about' to; speak. , '/When, ; a great earthquake occurred, people searched to ,find if there was a' volcano ,in the.neighbourhood,:. ; and if/ they/learnt that there was one within 1000 miles they, put; it dow.n as the cause of the 'earthquake. 'Seeing that.earthquakes which/shook , the whole world occurred: about twice 'every 'i.month, and that 'a/volcanic eruption/ usually ■lasted . aboutsix niomths, : it was to be expected, that events of the one class .would '.sometimes oc- . cur. simultaneously with events of' the .other class. The.Otago sounds and the Wanganui River.gorges were often talked:' about, as'vjf they ' werc'.-'due..to /earthquakes 0r.,, volcanic • action j. whereas the former/ wore of .* glacial origin aindthe : latter were due to the erosive operation/of the .river itself., Tho, notion that New Zealand was thrown up out of the sea by volcanic action N and.:would sink back again was /about, as ■ sensible : as. the Maori legend iihat Maui fished; it up out' l of the :oceari. : .; : ;' _ : '.•■■'■". '•■ ' . ■■"■■■'■'■ •'■ : i ,- ■'''•■ A fine.series of lantern views assisted the professor • to. giye a very clear,' exposition of the character of volcanic ■ action and: its etFects: on the surface of the earth. "Most of the pictures' were from the great central volcanic /region of this ,-island,'V'-including Ruapehu, ■ Nganruhoe, Tongariro, Tarawera, and the thernial regions, but the vicinity of Auckland city, with its 65 volcanic cones, was also graphically ■ treated; , arid the glorious cone -of was the' subject of several-.fine views, while foreign .countries ■were also laid-under contribution. Turning to the. theory of volcanoes, the lecturer gave some of the reasons why scientists, consider ■'that-'the'-steam which supplies the motive force of; volcanic outbursts does not come from: sea-water,' or. other. surface water leaking through to the hot jocks, but; was absorbed by the planet when it .was in a molten condition in the earliest stages: of its existence. '■•;..•..: ..'' . . .... .'■.■'; . -.. -: .• '.' The Wellington earthquake of 1855 was regarded as.the only : one in connection with which it was definitely proved that the level of land had beenraisea..-. Earthquakes.were due to sudden fractures of the earth's crust, which/sent ,a shudder through the crust for a'; greater or. lesser distance, according to .the intensity of the shock. These fractures'were caused by the shrinking of > the earth in the gradual process of its cooling. There was, as yet, no scientific means of foretelling the date and locality of an earthquake. ":': ■' ■.'/ '■ '■""': '- ■■'•. ' / ■'.'■ ./■ ' . ■'. "• The -lecturer, whose remarks had been followed with frequent marks of appreciation, received a.very hearty vote:of thanks.