1. Iceberg calving

Monitoring and modelling iceberg calving processes, including development and implementation of physically based 'calving laws' for ice sheet models (Benn et al., 2007a, b; Mottram and Benn, 2009; Nick et al., 2010; Luckman et al., 2015; Åström et al., 2013; Medrzycka et al., 2016; Benn et al., 2017a, b; How et al., 2017, 2019; Todd et al., 2018, in review; Vallot et al., 2018, 2019; Schild et al, 2018; Benn and Åström, 2018; Åström and Benn, 2019; Bevan et al., in review). The NERC-funded projects CALISMO and DOMINOS are yielding the next generation of calving models for Greenland and Antarctica, respectively, to reduce uncertainty in the ice sheet contribution to 21st C sea level rise. 

2. NSF/NERC International Thwaites Glacier Collaboration

Unstable retreat of Thwaites Glacier, West Antarctica, could raise mean global sea level by up to 1m in the 21st C under a high carbon scenario. DOMINOS is one of eight projects making up the International Thwaites Glacier Collaboration, which aims to reduce uncertainties over projected rates of sea level rise in response to alternative carbon futures. DOMINOS focuses on key processes of ice shelf disintegration and calving, which could possibly initiate collapse within a few decades. The prospect of rapid sea level rise has major implications for planning adaptation and risk management strategies worldwide. Results from DOMINOS will provide input for IPCC AR6, and are being disseminated via the GeoBus project, print and online media.

3. Glacier surges

Development of the first general theory of glacier surging, which can explain the full spectrum of glacier dynamic behaviour in a single framework (Benn et al., 2019a). The theory is based on the enthalpy budget of glacier systems and their interactions with local climates, and predicts that climate change can trigger step changes in glacier dynamics. The theory has been successfully tested against global-scale statistical data (Sevestre and Benn, 2015), and observations from individual glaciers (Sevestre et al., 2015, 2018; Benn et al., 2019b). 

4. Glacio-speleology

Application of glacio-speleology (ice caving) to glaciological problems, including making the first systematic investigations of internal glacial drainage systems in Svalbard and the Himalaya (Gulley and Benn, 2007; Gulley et al., 2009a, b; Benn et al. 2009a, b). Our ability to directly access and study glacial drainage systems has yielded a new understanding of water flow through glaciers, and its implications for glacier dynamics (Gulley et al., 2012, 2013; Makoff et al., 2017; Temminghof et al., 2018; Hansen et al., in review).       

5. Response of high mountain glaciers to climate change

Using field, remote sensing, and speleological data, we have shown how climate change triggers a complex cascade of effects in Himalayan glaciers, including increased melting, decreased flow velocity and stagnation, and retention of meltwater (Benn et al., 2001, 2012, 2017; Thompson et al., 2012; 2016). Together with detailed geophysical studies of moraine dam stability, this work provides a rational basis for prediction of outburst flood hazard risks in high mountain regions (Mertes et al., 2016; Benn et al., 2017; Thompson et al., 2017).

6. Snowball Earth 

An international team led by Ian Fairchild (University of Birmingham) demonstrated that orbital cycles exerted a key control on ice-sheet dynamics during Neoproterozoic panglaciations (Benn et al., 2015). This reconciles long-standing discrepancies between Snowball Earth theory and the geological record, and has set a new agenda for Neoproterozoic studies  (Fairchild et al., 2016; Fleming et al., 2016; Hoffman et al., 2017). I continue to collaborate with Ian Fairchild, Tony Spencer and others on the Neoproterozoic Port Askaig Formation in Scotland. 

Climate and weather systems, climate change