- journal_title：Geological Society of America Bulletin
- Contributor：Michael S. Fenster ; Duncan M. FitzGerald ; Joseph T. Kelley ; Daniel F. Belknap ; Ilya V. Buynevich ; Stephen M. Dickson
- Publisher：Geological Society of America
- Date：2001-
- Format：text/html
- Language：en
- Identifier：10.1130/0016-7606(2001)113<1522:NESTIA>2.0.CO;2
- journal_abbrev：Geological Society of America Bulletin
- issn：0016-7606
- volume：113
- issue：12
- firstpage：1522
Hydrographic data—obtained concurrently along the 25 km longitudinal axis of the Kennebec River estuary during a 13 h semidiurnal tidal cycle of a spring freshet superimposed on near-perigean spring tides—revealed a strong ebb-current dominance along the length of the estuary. Ebb- current dominance is produced by riverine flow that supplants a substantial part of the flood-tidal prism. In addition, side-scan sonograms showed a suite of large bed forms (1–12 m height) with nearly ubiquitous ebb orientations veneering the estuary bottom. Embayment geometry, salinity, water temperature, discharge, current velocity, and bed-form data all suggest that ebb- velocity asymmetry, set up by seasonal changes in freshwater discharge superimposed on ebb-directed tides, is the most important control on net bed-load sediment transport within this high-latitude, rock- bound estuary. These data augment a model that shows that a freshwater discharge threshold exists for net seaward bed-load sediment transport. The results from this study can be used to refine existing conceptual sedimentologic and morphologic classifications of estuaries.