Research Article| September 01, 1950 GEOPHYSICAL INVESTIGATIONS IN THE EMERGED AND SUBMERGED ATLANTIC COASTAL PLAIN: PART V: WOODS HOLE, NEW YORK, AND CAPE MAY SECTIONS MAURICE EWING; MAURICE EWING LAMONT GEOLOGICAL LABORATORY (COLUMBIA UNIVERSITY), PALISADES, N. Y. Search for other works by this author on: GSW Google Scholar J. L WORZEL; J. L WORZEL LAMONT GEOLOGICAL LABORATORY (COLUMBIA UNIVERSITY), PALISADES, N. Y. Search for other works by this author on: GSW Google Scholar N. C STEENLAND; N. C STEENLAND LAMONT GEOLOGICAL LABORATORY (COLUMBIA UNIVERSITY), PALISADES, N. Y. Search for other works by this author on: GSW Google Scholar FRANK PRESS FRANK PRESS LAMONT GEOLOGICAL LABORATORY (COLUMBIA UNIVERSITY), PALISADES, N. Y. Search for other works by this author on: GSW Google Scholar GSA Bulletin (1950) 61 (9): 877–892. https://doi.org/10.1130/0016-7606(1950)61[877:GIITEA]2.0.CO;2 Article history received: 18 Jul 1949 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation MAURICE EWING, J. L WORZEL, N. C STEENLAND, FRANK PRESS; GEOPHYSICAL INVESTIGATIONS IN THE EMERGED AND SUBMERGED ATLANTIC COASTAL PLAIN: PART V: WOODS HOLE, NEW YORK, AND CAPE MAY SECTIONS. GSA Bulletin 1950;; 61 (9): 877–892. doi: https://doi.org/10.1130/0016-7606(1950)61[877:GIITEA]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Seismic refraction measurements from the coast line to the edge of the continental shelf were made along three lines of traverse: near Cape May, N. J., New York, N. Y., and Woods Hole, Mass., respectively. An unconsolidated layer with velocity about 5800 ft/sec, a semiconsolidated layer with velocity about 11,500 ft/sec, and a layer, considered to be the basement, with velocity about 18,000 ft/sec were traced across each traverse.On the Cape May traverse, the thickness of the sedimentary column runs from about 5000 ft. near the beach to about 16000 ft. near the edge of the shelf, in general agreement with the findings on the Cape Henry traverse in 1935. The well on Cape Hatteras, which recently reached basement at 9878 feet, confirms the seismic results. The cross-section area of the sedimentary prism off Woods Hole is much less than that off New York, which in turn is less than that off Cape May. Depth to basement increases abruptly near the beach at Cape May, and about 30 miles off shore at New York. The basement starts to slope gently upward at or just before the edge of the continental shelf on these two profiles. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Measurements of gravity at sea, accurate enough to be of value in the problems of geodesy and geology, were first made by F. A. Vening Meinesz in 1923. Since that time Vening Meinesz has perfected his apparatus into a standard form and has made many highly important surveys with it [see 1 of references at end of paper]. The Vening Meinesz apparatus [2] contains three bronze half‐second pendulums, all mounted to swing in the same plane. By means of an ingenious optical system, the motions of the three pendulums are combined to give a photographic record of two fictitious pendulums, each fictitious pendulum being independent of small horizontal motions of the apparatus in the swinging‐plane of the pendulums. This instrument is installed in a submarine which submerges, when a gravity‐observation is to be made, and provides a platform relatively undisturbed by wave‐action.
One hundred and seventy-nine Lamont Geological Observatory heat-flow measurements in the Atlantic Ocean and the Caribbean Sea are presented; their reliability is carefully estimated. Together with 197 other measurements, they are used to describe the broad regional pattern of heat flow in the Atlantic Ocean. The average heat flow over the mid-Atlantic ridge is within 20% of the heat flow of the basins, and the absence of a wide heat-flow maximum in the observed values precludes the possibility of continuous continental drift during the Ceno-zoic by the spreading-floor mechanism in the Atlantic Ocean. In contrast, the excess of heat flow measured over the East Pacific rise is consistent with the existence of large convective transfer of heat in the underlying mantle.
Two dimensional model experiments on refractions from layers of finite thickness are described. Refractions can be unreliable for velocity and depth determinations when they occur with wavelengths which are large compared to the layer thickness. Discrepancies reported between refraction velocities and borehole velocities can be partially accounted for in this manner. Even simple two‐ and three‐layer models can show such effects as misleading second arrivals, echeloning of travel time curves, masked layers, and selective absorption in the overburden.
On February 1, 1951, between Olh 00m and 02h 00m EST, large barometric fluctuations were observed on a recording microbarograph at the Air Force laboratories at Watertown, Mass. This disturbance occurred with prefrontal activities of a warm front which passed through the area from the south at about 07h 30m EST on that date. Periods of fluctuations were about six minutes and peak‐to‐peak amplitudes about 1.0 mb. This barometric oscillation was not noted on nearby Weather Bureau barographs operating at drum speeds of 0.25 cm/hr, but was indicated on a barograph with a drum speed of about 1.1 cm/hr at the Blue Hill Observatory in Milton, Mass., about 11 miles south of Watertown. Here the disturbance has amplitudes of about 0.7 mb and periods of six to eight minutes. Tide records along the New England coasts did not show abnormal seiche activity, but such resonance phenomena are usually of longer periods than six minutes.
