19861, pp 445-489 Sci. Lett 109 I1 (I 9921. 22. We thank J. Cater, H. Adams, and D Schell~ng for 4 M. M. Sarn e t a / . , Geochim. Cosmochim. Acta 53, d~scuss~ons, samples, and unpubshed sedmento-997 (1989); K Pande et a1 Chem. Geol 11 6, 245 o g c a data from the Panir secton LASMO 0 1 Pak-(I 994) stan Ltd and the Drector General of Petroleum Con-5 M. R Palmer and J M. Edmond, Geochim Cosmochim Acta 56. 2099 11 992) cessons for provsion of samples and permisson to p u b s h data from the Panr secton, the Department of Soil Conservat~on n Babar Mahal, Kathmandu; and C. France-Lanord and L. Deriy for discussons and access to unpublished data. The early stages of this research were supported and encouraged by M McCulloch and A. Chivas at Australan Natona Unlverslty Th~s project was p r~m a r y funded by NSF grant EAR-941 8207.

[1] Results are presented from 70+ days of nearly continuous in situ acoustic imagery of the nearshore sandy seabed in $3-m mean water depth, at two locations separated by 40-m cross-shore distance. The bottom sediments were 150 mm median diameter sand, with nearly identical size distributions at the two locations. Five principal bed states were observed: irregular ripples, cross ripples, linear transition ripples, lunate megaripples, and flat bed. The linear transition and flat bed states were the most frequent, together accounting for 68% of the total time. Bed state occurrence was a strong function of incident wave energy, each bed state occurring within a relatively narrow range of seaand-swell energies. During the 12 major storm events spanned by the record, the bed response was characterized by a repeatable bed state storm cycle, involving four of the five principal states (lunate megaripples did not appear repeatedly, and thus may be a special case), with no obvious dependence of bed state occurrence on prior bed state, or on thirdmoment measures of wave nonlinearity. Radial spectra from the rotary acoustic images indicate pronounced differences in the anisotropy of spatial scales for the different bed states, and exhibit onshore-offshore differences which are likely related to ripple migration.Citation: Hay, A. E., and T. Mudge (2005), Principal bed states during SandyDuck97: Occurrence, spectral anisotropy, and the bed state storm cycle,

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We used a 5 year time series of transport, temperature, and salinity from moorings at the head of Barrow Canyon to describe seasonal variations and construct a 37 year transport hindcast. The latter was developed from summer/winter regressions of transport against Bering‐Chukchi winds. Seasonally, the regressions differ due to baroclinicity, stratification, spatial, and seasonal variations in winds and/or the surface drag coefficients. The climatological annual cycle consists of summer downcanyon (positive and toward the Arctic Ocean) transport of ∼0.45 Sv of warm, freshwaters; fall (October–December) upcanyon transport of ∼−0.1 Sv of cooler, saltier waters; and negligible net winter (January–April) mass transport when shelf waters are saline and near‐freezing. Fall upcanyon transports may modulate shelf freezeup, and negligible winter transports could influence winter water properties. Transport variability is largest in fall and winter. Daily transport probability density functions are negatively skewed in all seasons and seasonal variations in kurtosis are a function of transport event durations. The latter may have consequences for shelf‐basin exchanges. The climatology implies that the Chukchi shelf circulation reorganizes annually: in summer ∼40% of the summer Bering Strait inflow leaves the shelf via Barrow Canyon, but from fall through winter all of it exits via the western Chukchi or Central Channel. We estimate a mean transport of ∼0.2 Sv; ∼50% less than estimates at the mouth of the canyon. Transport discrepancies may be due to inflows from the Beaufort shelf and the Chukchi shelfbreak, with the latter entering the western side of the canyon.

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