This paper presents a new age‐depth relation and a comprehensive depth anomaly map for the Pacific Ocean. Age, depth, and sediment thickness were averaged for each 1°×1° area. Bathymetry was corrected for isostatic effects due to sediment and water load and for the variation of sound velocity in water. Seafloor existing at extreme distance from hot spot tracks is found to be anomalously deep. Hot spots were treated as thermal anomalies, and data within 800 km of them were eliminated from further analysis. An age‐depth equation was determined by fitting a least squares line to the remaining data. The resulting depth versus age distribution confirms the linear dependence of depth on √age up to 80 Ma. All older seafloor is within 800 km of hot spots or hot spot tracks and is shallower than predicted. This “flattening” of the age‐depth distribution requires that a separate function be fit to data older than 80 Ma. As a result, data representing the deepest seafloor (older than 80 Ma) were selected for curve fitting, and the age‐depth distribution was approximated by an exponential function. It is impossible to distinguish between the infinite half space and cooling plate models of the lithopshere using the age‐depth data from the Pacific Ocean. A depth anomaly map prepared by comparing observed depth with the depth predicted by the new age‐depth formula shows several newly recognized features, including swells over the Louisville Ridge in the South Pacific and in the Gulf of Alaska Seamounts.

[1] The annual cycle of the surface salinity field in the eastern Gulf of Mexico (GoM) basin is investigated with a numerical model and observational data. A tongue of low salinity water is evident in the model climatology spreading southward from the Mississippi -Alabama -Florida (MAFLA) shelf and De Soto Canyon in the summer. The model salinity climatology along this path compares well to historical observations. This climatological feature is a consequence of the seasonal availability of low salinity water over the MAFLA shelf and De Soto Canyon for entrainment into jets associated with the mesoscale eddy field in the northern GoM. Additionally, the chlorophyll a monthly climatology from satellite data shows elevated concentrations in a tongue-like pattern similar to the low salinity feature found in the model, suggestive of a biological connection between the eastern GoM basin and river discharge in the northern GoM.

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The Ningaloo Current (NC) is a wind-driven, northward-flowing current present during the summer months along the continental shelf between the latitudes of 22° and 24°S off the coastline of Western Australia. The southward flowing Leeuwin Current is located further offshore and flows along the continental shelf break and slope, transporting warm, relatively fresh, tropical water poleward. A recurrent feature, frequently observed in satellite images (both thermal and ocean colour), is an anti-clockwise circulation located offshore Point Cloates. Here, the seaward extension of the coastal promontory blocks off the broad, gradual southern shelf, leaving only a narrow, extremely steep shelf to the north. The reduction in the cross-sectional area, from the coast to the 50 m contour, between southward and northward of the promontory is ~80%. Here, a numerical model study is undertaken to simulate processes leading to the development of the recirculation feature offshore Point Cloates. The numerical model output reproduced the recirculation feature and indicated that a combination of southerly winds, and coastal and bottom topography, off Point Cloates is responsible for the recirculation. The results also demonstrated that stronger southerly winds generated a higher volume transport in the NC and that the recirculation feature was dependent on the wind speed, with stronger winds decreasing the relative strength of the recirculation.

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