Being the deepest of all nearshore environments (up to 1300 m), fjords can acquire great thicknesses (up to 800 m) of unconsolidated Late Quaternary sediments. Such extreme water depths so close to land, point to the erosive power of glaciers that carved the fjords. Glacial erosion rates depend on several factors, especially ice velocity (<0.1 to >10 km/y), the shear stress at the base of the ice, and substrate properties. Twenty-five percent of world’s fjords currently contain marine-terminating or tidewater glaciers.

Sediment fill of fjords is strongly influenced by the magnitude of local sea level. Fjords that deglaciated early (~16 ky) are initially affected by regional isostasy, and then by changes in ocean volume (eustasy). Fjords that deglaciated later (say 5 ky ago) are mostly influenced by isostasy, having largely missed the main eustatic sea level rise of 120 m from about 16 to 7 kyr BP.

Fjord deposits reflect five depositional environments: (1) Ice-contact diamicton associated with grounding line fans, lodgment till and other morainal deposits, deposited at rates up to 100 cm/y; (2) Ice-proximal glacimarine sands and diamicton deposited rapidly (~4–12 cm/y) within a few km from a tidewater ice margin; (3) Ice-distal glacimarine muds, sometimes varved, along with dropstones that record hemipelagic sedimentation (~1–3 cm/y) away from the direct influence of ice front dynamics; (4) Paraglacial gravels, sands and muds deposited (~0.3 – 0.8 cm/y) that record the terrestrial ablation of ice sheets and caps, including the supply sediment along fjord valleys, made available as uplifted marine and fluvial terraces, and as transported by excess discharge of an ablating ice mass; (5) Postglacial sands and muds deposited at rates of ~0.1 – 0.4 cm/y, and gravelly-sandy lags that record modern ocean dynamics, outside of the influence of an ice sheet. Sediment accumulating in fjords during the paraglacial and postglacial phases reflect not only the duration of sediment input, but also the complexities of global versus local sea level rise. Geometry also strongly influences the apparent accumulation rates in fjords.

The sediment volume defining each deposit type depends on the energy supplying the sediment, and the duration of a particular sedimentary environment. With few exceptions, glacial meltwater loads are 10-fold larger than sediment fill rates associated with postglacial loads. For example, of the 80 to 350 m of sediment fill associated with ten Baffin Island fjords, postglacial sediments deposited during the last 6000 years account for <10 m of the sediment columns. Fjord stratigraphic styles include: (1) conformable deposits from hemipelagic sedimentation, (2) onlapping basin fill from decreasing wave or tidal energy with water depth, (3) ponded deposits from sediment gravity flows, (4) deposit wedging from tidal currents, (5) complex stratigraphic patterns associated with both the modern dominant processes, and processes that no longer are present. Fjords with seasonal ice-cover, magnify the seasonality of deep-basin sediment flux, by limiting the wintertime sediment delivery from rivers, by aeolian transport, and wind-wave resuspension transport.

After 45 years of research on fjords, I claim John T Andrews as my most important mentor and colleague. John and I first sailed into Baffin Fjords in 1982, and later into Greenland fjords in 1993, resulting in many useful papers on fjord sedimentation.