About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
Journal of Sedimentary Research (SEPM)
Abstract
Internal-Wave Currents as a Mechanism to Account for Large Sand
Waves
in Navarinsky Canyon
Head
, Bering Sea
H. A. Karl, D. A. Cacchione, P. R. Carlson
ABSTRACT
Sand waves
are found in the heads of four of five large submarine canyons that incise the northern continental margin of the Bering Sea. The sand
waves
occur in a restricted depth zone of about 175-490 m. Those in Navarinsky Canyon, the area surveyed in most detail, are best developed in water depths of 300-375 m; they average 5 m in height and about 650 m in wavelength, with crests oriented subparallel to isobaths and almost perpendicular to the axes of the two main branches of the canyon.
We speculate that internal-wave currents are responsible for the sand waves
. Currents generated by internal
waves
are a particularly attractive mechanism for at least three reasons: 1) the energy of the internal
waves
could be amplified in the
head
of Navarinsky Canyon, especially in the area of the sand wave field; 2) upslope boundary-
layer
intensification of internal-wave currents might be sufficient to move the sediment composing the sand
waves
; and 3) the wavelengths of higher-frequency internal
waves
closely match the spacing of the sand
waves
.
Although we based our assumptions on present-day conditions, we do not know if the sand waves
are active. Consequently, we do not discount the possibility that the sand
waves
could have originated in the Pleistocene when Navarinsky Canyon headed in a shallow embayment that was receiving large quantities of sediment discharged by glacial meltwater streams. These conditions probably caused strong vertical density gradients in the coastal waters, which would have been more favorable than those today for the propagation of high-frequency internal
waves
.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |