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WonderOcean mapping biography

Marie Tharp, an American geologist, drew the first detailed maps of the Atlantic seafloor from ships' depth readings. In the early 1950s she found a deep valley running along the middle of the undersea Mid-Atlantic Ridge, strong evidence that the seafloor is spreading apart.

Marie Tharp

ScienceOceanBiography

The story behind the card

Tharp joined Columbia University's Lamont Geological Observatory in New York in 1948. Women were not allowed to work on its research ships, so for nearly two decades her colleague Bruce Heezen collected echo-sounder depth readings at sea while she turned them into profiles and maps ashore. In 1952 she spotted a V-shaped valley along the crest of the Mid-Atlantic Ridge, an undersea mountain chain longer than any range on land, and read it as a rift where the seafloor is pulling apart. Heezen at first dismissed it as 'girl talk', because it supported continental drift, then a controversial idea. He changed his mind when a separate map of undersea earthquakes lined up with her valley. With the Austrian painter Heinrich Berann, they published The World Ocean Floor map in 1977.

Türkçe oku
Amerikalı jeolog Marie Tharp, gemilerin topladığı derinlik ölçümlerinden Atlantik Okyanusu tabanının ilk ayrıntılı haritalarını çizdi. 1950'lerin başında, okyanusun altındaki Orta Atlantik Sırtı'nın tam ortası boyunca uzanan derin bir vadi buldu. Bu, deniz tabanının iki yana doğru açıldığının güçlü bir kanıtıydı.

Tharp, 1948'de Columbia Üniversitesi'ne bağlı Lamont Jeoloji Gözlemevi'nde çalışmaya başladı. Kadınların araştırma gemilerinde çalışmasına izin verilmediği için yaklaşık yirmi yıl boyunca meslektaşı Bruce Heezen denizde yankı iskandiliyle derinlik ölçtü, Tharp da bu verileri karada kesitlere ve haritalara dönüştürdü. 1952'de, karadaki her sıradağdan daha uzun olan su altı sıradağı Orta Atlantik Sırtı'nın doruğu boyunca uzanan V biçiminde bir vadi fark etti ve bunu deniz tabanının iki yana çekildiği bir yarık olarak yorumladı. Heezen, o dönem tartışmalı olan kıtaların kayması fikrini desteklediği için bunu önce “kız dedikodusu” diye küçümsedi. Su altı depremlerini gösteren ayrı bir harita vadiyle neredeyse birebir örtüşünce fikrini değiştirdi. İkili, Avusturyalı ressam Heinrich Berann ile birlikte 1977'de Dünya Okyanus Tabanı haritasını yayımladı.

Sources and further reading

Background reading: Marie Tharp
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