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In the Otway Basin, the early Cretaceous Crayfish Sub-group infills syn-rift half grabens and has produced petroleum and commercial volumes of CO2. Naturally occurring Hydrogen has also been recorded in historic exploration wells. Previous work focusing on the depositional environment and tectonostratigraphic evolution within the depocenters indicates that variations in accommodation and sediment supply strongly influences the stratigraphic architecture of the Crayfish Sub-group. To evaluate this influence, we use a landscape and basin evolution numerical model (Badlands). First, we generate a series of simulations with varied tectonic, climate and erodibility parameters using a design of experiments method. From these, we select scenarios with a correspondence between the modelled and observed stratigraphy of the Crayfish Sub-group at specified well locations. We then propose that the observed stratigraphy of the Otway Basin Crayfish Sub-group can be explained by sediment supply variations caused by the evolution of the surrounding landscape across four phases which are: Phase 1: Limited sediment supply as the drainage systems start to develop in response to the rift formation. Phase 2: Sediment supply peaks as high erosion in the steep rift escarpment proximal to the depocenters increases sediment volumes delivered to the depocenters. Phase 3: Relatively high sediment supply continues thanks to an efficient connection between upstream region and the depocenter. Phase 4: Differential sediment supply controlled by a distal and a proximal source. Sediment from the distal escarpment is supplied at a constant rate and buffered within the landscape, while proximal, high sediment supply pulses are generated when the proximal rift escarpments steepen. By extending and quantifying existing conceptual models that link stratigraphy to sediment supply and accommodation, this work demonstrates how source-to-sink models enhance our understanding of the complex stratigraphy taking place within rift systems., Open-Access Online Publication: May 29, 2023

Aim: Given the availability of both public health and social measures (PHSMs) and safe and highly-effective vaccines against covid-19, we aimed to assess the feasibility of covid-19 eradication, relative to the benchmarks of smallpox and polio (albeit only 2 of 3 polio serotypes eradicated to date).Methods: Our scoring system was partly based on previously published factors favouring the eradicability of vaccine-preventable diseases. But it was also supplemented by additional technical, socio-political, and economic factors that we considered relevant.Results: On our scoring for eradication feasibility using a three-point scale and across 17 variables, the mean (total) scores were smallpox at 2.7 (43/48), then covid-19 at 1.8 (30/51), and then polio at 1.5 (26/51). More specifically for covid-19 eradication, animal reservoirs may potentially prevent it; but the main challenges are probably around the high upfront costs and achieving international cooperation. Nevertheless, an advantage for covid-19 eradication over these other diseases is that effective PHSMs can complement vaccination and there is very high global interest in covid-19 control (due to the massive scale of the health, social and economic burden).Conclusions: In this preliminary analysis, the feasibility of covid-19 eradication globally seems slightly more feasible than for polio, but much less than for smallpox eradication. There is a need for a more formal expert review of feasibility and desirability of attempting covid-19 eradication by the World Health Organization or coalitions of national health agencies.