On the deflection of the plumb-line and variations of gravity in the Hawaiian Islands

Author:

Preston, E. D. (Erasmus Darwin)

Title:

On the deflection of the plumb-line and variations of gravity in the Hawaiian Islands

Periodical:

American Journal of Science

Year:

1888

Volume:

36

Pages:

305-317

Subject:

Geology Hawaii Island Gravity Mauna Kea

Summary:

In this study, the author uses gravity measurements to estimate the bulk density of Haleakala as 2.4. He notes that plumb lines at Kohala (Hamakua Coast) and at Hilo are deflected toward each other. The southward deflection at Kohala is due to the mass of the large volcanoes, Mauna Kea and Mauna Loa. The northward deflection at Hilo cannot be so explained, unless the active volcanoes are less dense than the inactive ones. Preston concludes that (1) deflections of the plumb-line are greater on island than on continental mountains, presumably on account of the lighter surrounding sea water; (2) deflections appear to be greater in the vicinity of extinct volcanoes than near active ones; and (3) the so-called "hidden causes", which in the case of the Himalayas give a variation of gravity several times as great as those arising from the attraction of the mountains themselves, do not exist in the Hawaiian Islands.

URL:

https://www.proquest.com/openview/6b22c45124dbf46d77ca1132faf9a39a/1

Date:

November 1888

Collection:

Periodicals