The linked reference introduce sub-glacial hydrology mechanisms into the PISM ice model which they calibrate to Heinrich Events and then apply the calibrated model to ice in the Siple Coast region of West Antarctica:
Feldmann, J. and Levermann, A.: From Heinrich Events to cyclic ice streaming: the grow-and-surge instability in the Parallel Ice Sheet Model, The Cryosphere Discuss., doi:10.5194/tc-2016-235, in review, 2016.
http://www.the-cryosphere-discuss.net/tc-2016-235/Abstract. Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermo-mechanically coupled model on 1 km horizontal resolution includes an enthalpy-based formulation of the thermodynamics, a non-linear stress-balanced based sliding law and a very simple sub-glacial hydrology. The simulated unforced surging is characterized by rapid ice streaming through a bed trough, resulting in abrupt discharge of ice across the grounding line which is eventually calved into the ocean. We identify and visualize the central feedbacks that dominate the sub-sequent phases of ice build-up, surge and stabilization which emerge from the interaction between ice dynamics, thermodynamics and the sub-glacial till layer. A reduction in the surface mass balance or basal roughness yields a damping of the feedback loop which suggests that thinner ice sheets may be less susceptible to surging. The presented mechanisms underlying our simulations of self-maintained, periodic ice growth and destabilization may play a role in large-scale ice-sheet surging, such as the surging of the Laurentide Ice Sheet, which is associated with Heinrich Events, and ice-stream shut-down and reactivation, such as observed in the Siple Coast region of West Antarctica.
Also, in the Science folder & the "Sea Level Rise: New Iceberg Theory" thread, sidd posted the following related Reply #2:
http://forum.arctic-sea-ice.net/index.php/topic,455.0.html"Nice model from Feldmann and Levermann giving ice surges with a realistic (PISM) ice model. Open access
doi:10.5194/tc-2016-235
"During the surge phase mainly the process of hydraulic runaway (positive feedback between basal melt water production and flow acceleration; Fowler and Johnson, 1995) is in effect. It is complemented by creep instability (positive feedback between strain heating and ice deformation; Clarke et al., 1977), which additionally promotes rapid ice streaming [Ref. 20] (Figs. 4 and 5). The modeled cyclic alternation of ice streaming and stagnation provides a simple example of ice-stream shutdown and re-activation, a phenomenon which is characteristic for the dynamics of some of the Siple Coast outlets in West Antarctica.
The period duration of a full surge cycle in our model of about 1.8 kyr is very close to results from other recent studies (Bougamont et al., 2011; Robel et al., 2016) which is surprising considering the differences in degree of physical approximations, [Ref 25] parameterizations, and setup complexity between the three studies"."