Interglacials are warm intervals in Earth's climatic history characterized by high global average temperatures, reduced ice sheet extent, and higher-than-present sea levels. Geological records from many sites around the globe allow the identification of several interglacials that have occurred since the late Pliocene, each different in height and duration of peak sea level and wave intensity. Studying these periods is particularly pertinent for unravelling sea-level oscillations and wave regime variations and refining models of polar ice melting in the near future. The relative sea level (RSL) and wave conditions are reconstructed using geological and biological sea-level proxies, which are formed in relation to the past position of the sea level. Although we comprehensively understand global sea-level dynamics during the current interglacial (Holocene), our knowledge of these dynamics during past interglacials remains limited. Hence, a compendium of sea-level and wave condition proxies, over the multi-millennial scale of multiple interglacials, will help in assessing sea-level impacts in a future warmer world.

This special issue invites the international sea-level community to present studies broadly related to sea level and coastal geological processes during the Plio-Pleistocene interglacials. We welcome studies presenting new field data and re-analysis of previously published data with new techniques and new models of coastal processes in the past including hydrodynamics and geodynamics. We also welcome contributions to geochronology methods and remote sensing techniques applied to constrain sea-level proxies in both active and steady tectonic settings.

Two closely coordinated groups (one from the USA and the other from Europe) are revisiting the Camp Century sub-ice sediment and the silty ice zone just above it using a wide variety of analytical techniques to make inferences about ice sheet behaviour, palaeo-climate, and palaeo-ecology as well as sediment transport and sourcing. The paper that kicked this off was in Proceedings of the National Academy of Sciences (PNAS) 2 years ago: "A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century" (Christ et al., 2021).

Talking among the 20+ lead investigators, we decided that the papers coming out of multiple, coordinated investigations of this historic (and still unique) ice core would be very useful to the broader community if they could be gathered into a special issue. Having these papers together would increase their impact and accessibility. Because of the wide variety of investigations being conducted on the core materials, a combined special issue including papers from both The Cryosphere and Climate of the Past will generate the most contributions and the largest readership.

Reference:

Christ, A. J., Bieman, P. R., Schaefer, J. M., Dahl-Jensen, D., Steffensen, J. P, Corbett, L. B., Peteet, D. M., Thomas, E. K., Steig, E. J., Rittenour, T. M., Tison, J.-L., Blard, P.-H., Perdrial, N., Dethier, D. P., Lini, A., Hidy, A. J., Caffee, M. W., and Southon, J.: A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century, P. Natl. Acad. Sci. USA, 118, e2021442118, https://doi.org/10.1073/pnas.2021442118, 2021.

Interglacials are warm intervals in Earth's climatic history characterized by high global average temperatures, reduced ice sheet extent, and higher-than-present sea levels. Geological records from many sites around the globe allow the identification of several interglacials that have occurred since the late Pliocene, each different in height and duration of peak sea level and wave intensity. Studying these periods is particularly pertinent for unravelling sea-level oscillations and wave regime variations and refining models of polar ice melting in the near future. The relative sea level (RSL) and wave conditions are reconstructed using geological and biological sea-level proxies, which are formed in relation to the past position of the sea level. Although we comprehensively understand global sea-level dynamics during the current interglacial (Holocene), our knowledge of these dynamics during past interglacials remains limited. Hence, a compendium of sea-level and wave condition proxies, over the multi-millennial scale of multiple interglacials, will help in assessing sea-level impacts in a future warmer world.

This special issue invites the international sea-level community to present studies broadly related to sea level and coastal geological processes during the Plio-Pleistocene interglacials. We welcome studies presenting new field data and re-analysis of previously published data with new techniques and new models of coastal processes in the past including hydrodynamics and geodynamics. We also welcome contributions to geochronology methods and remote sensing techniques applied to constrain sea-level proxies in both active and steady tectonic settings.

Two closely coordinated groups (one from the USA and the other from Europe) are revisiting the Camp Century sub-ice sediment and the silty ice zone just above it using a wide variety of analytical techniques to make inferences about ice sheet behaviour, palaeo-climate, and palaeo-ecology as well as sediment transport and sourcing. The paper that kicked this off was in Proceedings of the National Academy of Sciences (PNAS) 2 years ago: "A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century" (Christ et al., 2021).

Talking among the 20+ lead investigators, we decided that the papers coming out of multiple, coordinated investigations of this historic (and still unique) ice core would be very useful to the broader community if they could be gathered into a special issue. Having these papers together would increase their impact and accessibility. Because of the wide variety of investigations being conducted on the core materials, a combined special issue including papers from both The Cryosphere and Climate of the Past will generate the most contributions and the largest readership.

Reference:

Christ, A. J., Bieman, P. R., Schaefer, J. M., Dahl-Jensen, D., Steffensen, J. P, Corbett, L. B., Peteet, D. M., Thomas, E. K., Steig, E. J., Rittenour, T. M., Tison, J.-L., Blard, P.-H., Perdrial, N., Dethier, D. P., Lini, A., Hidy, A. J., Caffee, M. W., and Southon, J.: A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century, P. Natl. Acad. Sci. USA, 118, e2021442118, https://doi.org/10.1073/pnas.2021442118, 2021.