Bryozoan Tabulipora carbonaria in Wreford Megacyclothem (Lower Permian) of Kansas

96 p., 9 pl., 33 fig.http://paleo.ku.edu/contributions.htm

Fistuliporacean bryozoans of the Wreford megacyclothem (Lower Permian) of Kansas

24 p., 3 pl., 5 fig.http://paleo.ku.edu/contributions.htm

Fenestrate, Pinnate, and Ctenostome Bryozoans and Associated Barnacle Borings in the Wreford Megacyclothem (Lower Permian) of Kansas, Oklahoma, and Nebraska

38 p., 11 fig., 11 tables.http://paleo.ku.edu/contributions.htm

Stratigraphic and Geographic Bryozoan Abundance Gradients in the Calcareous Shales of the Wreford Megacyclothem (Lower Permian, Kansas)

17 p., 3 fig., 13 tables.http://paleo.ku.edu/contributions.htm

Filiramoporina kretaphilia-a new genus and species of bifoliate tubulobryozoan (Ectoprocta) from the Lower Permian Wreford Megacyclothem of Kansas

12 p., 2 pl., 3 fig.http://paleo.ku.edu/contributions.htm

Contrasting the modelled sensitivity of the Amundsen Sea Embayment ice streams

Present-day mass loss from the West Antarctic ice sheet is centred on the Amundsen Sea Embayment (ASE), primarily through ice streams, including Pine Island, Thwaites and Smith glaciers. To understand the differences in response of these ice streams, we ran a perturbed parameter ensemble, using a vertically-integrated ice flow model with adaptive mesh refinement. We generated 71 sets of three physical parameters (basal traction coefficient, ice viscosity stiffening factor and sub-shelf melt rate), which we used to simulate the ASE for 50 years. We also explored the effects of different bed geometries and basal sliding laws. The mean rate of sea-level rise across the ensemble of simulations is comparable with current observed rates for the ASE. We found evidence that grounding line dynamics are sensitive to features in the bed geometry: simulations using BedMap2 geometry resulted in a higher rate of sea-level rise than simulations using a rougher geometry, created using mass conservation. Modelled grounding-line retreat of all the three ice streams was sensitive to viscosity and basal traction, while the melt rate was more important in Pine Island and Smith glaciers, which flow through more confined ice shelves than Thwaites, which has a relatively unconfined shelf

A Thin Film Viscoplastic Theory for Calving Glaciers: Toward a Bound on the Calving Rate of Glaciers

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151877/1/jgrf21080.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151877/2/jgrf21080_am.pd

Redescription of Syntypes of the Bryozoan Species Rhombyotrypa quadrata (Rominger)

37-45http://deepblue.lib.umich.edu/bitstream/2027.42/48383/2/ID228.pd

Climate Noise Influences Ice Sheet Mean State

Evidence from proxy records indicates that millennial‐scale abrupt climate shifts, called Dansgaard‐Oeschger events, happened during past glacial cycles. Various studies have been conducted to uncover the physical mechanism behind them, based on the assumption that climate mean state determines the variability. However, our study shows that the Dansgaard‐Oeschger events can regulate the mean state of the Northern Hemisphere ice sheets. Sensitivity experiments show that the simulated mean state is influenced by the amplitude of the climatic noise. The most likely cause of this phenomenon is the nonlinear response of the surface mass balance to temperature. It could also cause the retreat processes to be faster than the buildup processes within a glacial cycle. We propose that the climate variability hindered ice sheet development and prevented the Earth system from entering a full glacial state from Marine Isotope Stage 4 to Marine Isotope Stage 3 about 60,000 years ago