Dynamic Topography and Ice Age Paleoclimate

Abstract

The connection between the geological record and dynamic topography driven by mantle convective flow has been established over widely varying temporal and spatial scales. As observations of the process have increased and numerical modeling of thermochemical convection has improved, a burgeoning direction of research targeting outstanding issues in ice age paleoclimate has emerged. This review focuses on studies of the Plio-Pleistocene ice age, including investigations of the stability of ice sheets during ice age warm periods and the inception of Northern Hemisphere glaciation. However, studies that have revealed nuanced connections of dynamic topography to biodiversity, ecology, ocean chemistry, and circulation since the start of the current ice-house world are also considered. In some cases, a recognition of the importance of dynamic topography resolves enigmatic events and in others it confounds already complex, unanswered questions. All such studies highlight the role of solid Earth geophysics in paleoclimate research and undermine a common assumption, beyond the field of glacial isostatic adjustment, that the solid Earth remains a rigid, passive substrate during the evolution of the ice age climate system. ▪ Dynamic topography is the large-scale, vertical deflection of Earth's crust driven by mantle convective flow. ▪ This review highlights recent research exploring the implications of the process on key issues in ice age paleoclimate. ▪ This research includes studies of ice sheet stability and inception as well as inferences of peak sea levels during periods of relative ice age warmth. ▪ This review also includes studies on longer timescales, continental-scale ecology and biodiversity, the long-term carbon cycle, and water flux across oceanic gateways.

Comparison and Synthesis of Sea‐Level and Deep‐Sea Temperature Variations Over the Past 40 Million Years

“…Corrections for various lithospheric and/or sea‐bed movement types are needed to translate observed RSL changes into GMSL changes, which commonly also account for gravitational and rotational impacts of large (ice‐sheet) mass changes on Earth's surface (e.g., Austermann et al., 2017; Braun, 2010; J. A. Clark et al., 1978; Ferrier et al., 2017; Gomez, Mitrovica, Huybers, & Clark, 2010; Gomez, Mitrovica, Tamisiea, & Clark, 2010; Gregory et al., 2019; Kuchar et al., 2020; Lambeck & Chappell, 2001; Lambeck et al., 2011, 2014; Milne & Mitrovica, 1998, 2008; Mitrovica & Milne, 2003; Mitrovica & Peltier, 1991; Mitrovica et al., 2001, 2020; Moucha et al., 2008; Nakada & Lambeck, 1987; Nakiblogu & Lambeck, 1980; Peltier, 1988, 1994, 1998, 2004; Peltier & Fairbanks, 2006; Peltier et al., 2015; Raymo et al., 2011; Rovere et al., 2014; Rowley et al., 2013; Tamisiea & Mitrovica, 2011; Vermeersen & Schotman, 2009; Whitehouse, 2018; Yokoyama & Purcell, 2021). Such corrections carry uncertainties because of the choice of model and model parameters used (e.g., Dumitru et al., 2019, 2021; K. M. Grant et al., 2014; Kuchar et al., 2020; Milne & Mitrovica, 2008; Peak et al., 2022; Raymo et al., 2011; Rohling et al., 2017; Whitehouse, 2018).…”

“…Coral data are also typically limited by relatively short temporal coverage over just two or three glacial cycles (∼350,000 years), and can suffer from habitat‐depth uncertainties and region‐specific environmental impacts (e.g., Braithwaite, 2016; Hibbert et al., 2016, 2018; Rohling et al., 2017, 2019; C. D. Woodroffe & Webster, 2014). Finally, all RSL methods require corrections for vertical land movements due to tectonic, GIA, and dynamic topography effects (e.g., Austermann et al., 2017; Milne & Mitrovica, 2008; Mitrovica et al., 2020; Peak et al., 2022; Rovere et al., 2014). Regardless, comparison of RSL records with ice‐volume (or GMSL) records remains valuable, even without crustal movement corrections, because of the independent age control of various RSL records on rapid transitions.…”

“…D. Woodroffe & Webster, 2014). Finally, all RSL methods require corrections for vertical land movements due to tectonic, GIA, and dynamic topography effects (e.g., Austermann et al, 2017;Milne & Mitrovica, 2008;Mitrovica et al, 2020;Peak et al, 2022;Rovere et al, 2014). Regardless, comparison of RSL records with ice-volume (or GMSL) records remains valuable, even without crustal movement corrections, because of the independent age control of various RSL records on rapid transitions.…”

Observational Estimates of Dynamic Topography Through Space and Time

“…This interdisciplinary review reflects our increasing understanding of the influence of dynamic topography in shaping the rock record, which has important implications for volcanic systems, oceanic circulation, ice sheet dynamics, and interpretation of paleoclimatic records (e.g. Mitrovica et al, 2020). Improving observational, computational and theoretical constraints on mantle convection is therefore a fundamental goal of our community, with important ramifications for many areas of Earth sciences.…”

Fernandes and Roberts (2020) - preprint

“…For example, the elevation, history and erosion of topography are crucial components for understanding chemical fluxes to the oceans, weathering, atmospheric and oceanic circulation and biotic distributions (e.g., Raymo and Ruddiman, 1992;Anderson and Anderson, 2010;Herman et al, 2013;Perrigo et al, 2019). As such, topographic evolution plays a central role in understanding climate change throughout geological time (Mitrovica et al, 2020). Despite more than 100 years of study, defining and understanding histories of topographic growth and decay on geologic timescales remain important topics of research (e.g., Davis, 1899;Suess, 1906;Hack , 1975;Ziegler et al, 1985;Sahagian, 1987;Mitrovica et al, 1989;McDonough and Cross, 1991;Rowley, 2013).…”