Glacial and interglacial intensities across the Mid-Pleistocene Transition from a new 1.5 Myr long compilation of marine and terrestrial records

Abstract. The Mid-Pleistocene Transition (MPT), between 1.2 and 0.8 Ma, altered the amplitude and frequency of Quaternary glacial–interglacial cycles with varying regional and proxy-dependent effects. Efforts to characterize these differences are constrained by the scarcity of continuous, high-resolution terrestrial archives, in contrast to the relative abundance of marine sediment cores. Previous compilations have focused on only the last 800 kyr or solely on marine records, and thus have not captured the full expression of the MPT across different proxies and for the pre- and post-MPT world. In this study, we present a new compilation of 29 paleoclimatic records spanning the last 1.5 Myr with equal contributions from marine and terrestrial archives. Interglacial and glacial strength is assessed for each record. This reveals a glacial amplification in strength from Marine Isotope Stage (MIS) 22 onwards, around 930 ka, which is evident in both the marine and terrestrial archives. For the past 1.5 Myr, there is no consistent temporal trend in interglacial strength visible in the terrestrial records. In contrast, the interglacial patterns of the marine records agree with previous studies, which are characterized by relatively strong interglacials during early stages (MIS 49–43) and following the Mid-Brunhes Shift (MBS), and more subdued interglacials during MIS 29–13a. A consistently strong global signal is detected during interglacial MIS 31 across most archives. MIS 13a emerges as a particularly interesting stage, as it appears weak in marine archives but strong in several terrestrial records, indicating that the manifestation of the MPT was not homogeneous between the marine and continental climate systems. Moreover, our compilation indicates a strong linear relationship between interglacial strength and the preceding glacial strength in benthic δ¹⁸O records since the MBS. For other archive types, we identify notably strong post-MBS interglacials during MIS 5e, 9e, and 11c, each of which follows a strong glacial interval. However, there is no consistent linear relationship in intensity evident across these archives. Furthermore, most records indicate distinct interglacial and glacial states, separated by their value ranges. To facilitate the exploration of the presented archives, we provide an interactive web-based dashboard that allows users to investigate the compiled records and their associated glacial and interglacial intensities. The compiled archives, especially the newly compiled terrestrial records, will be essential for future efforts to derive chronologies synchronised across different archives and as targets for model-data comparisons across the MPT.