ALBERT

Description: The VOLCORE (Volcanic Core Records) database is a collection of 34,696 visible tephra (volcanic ash and associated products) occurrences reported in the initial reports volumes of all of the Deep Sea Drilling Project (DSDP; 1966-1983), the Ocean Drilling Program (ODP; 1983-2003), the Integrated Ocean Drilling Program (IODP; 2003-2013) and the International Ocean Discovery Program (IODP; 2013-present) up to and including IODP Expedition 381. The combined international drilling programmes (OD) have locations with global coverage. Cored tephra layers and tephra-bearing sediments span timescales from recent to ~150 million years in age. This database is a collection of information about reported visible tephra layers entirely or predominantly composed of volcanic ash. Data include the depth below sea floor, tephra thickness, location, and any reported comments. An approximate age was estimated for most (29,493) of the tephra layers using available age-depth models. The database can be applied to tephrochronology, volcanology, geochemistry, studies of sediment transport and palaeoclimatology.

Description: VOLCORE_2021 is an update on the original VOLCORE data released in 2020. Change notes are listed within the VOLCORE_2021 data file. A major update is the new merged Layers-Holes-AgeDepth sheet, enabling easier manipulation of the data. The VOLCORE (Volcanic Core Records) database is a collection of 34,696 visible tephra (volcanic ash and associated products) occurrences reported in the initial reports volumes of all of the Deep Sea Drilling Project (DSDP; 1966-1983), the Ocean Drilling Program (ODP; 1983-2003), the Integrated Ocean Drilling Program (IODP; 2003-2013) and the International Ocean Discovery Program (IODP; 2013-present) up to and including IODP Expedition 381. The combined international drilling programmes (OD) have locations with global coverage. Cored tephra layers and tephra-bearing sediments span timescales from recent to ~150 million years in age. This database is a collection of information about reported visible tephra layers entirely or predominantly composed of volcanic ash. Data include the depth below sea floor, tephra thickness, location, and any reported comments. An approximate age was estimated for most (29,493) of the tephra layers using available age-depth models. The database can be applied to tephrochronology, volcanology, geochemistry, studies of sediment transport and palaeoclimatology.

Description: We have produced a global dataset of ~4000 GPS vertical velocities that can be used as observational estimates of glacial isostatic adjustment (GIA) uplift rates. GIA is the response of the solid Earth to past ice loading, primarily, since the Last Glacial Maximum, about 20 K yrs BP. Modelling GIA is challenging because of large uncertainties in ice loading history and also the viscosity of the upper and lower mantle. GPS data contain the signature of GIA in their uplift rates but these also contain other sources of vertical land motion (VLM) such as tectonics, human and natural influences on water storage that can mask the underlying GIA signal. A novel fully-automatic strategy was developed to post-process the GPS time series and to correct for non-GIA artefacts. Before estimating vertical velocities and uncertainties, we detected outliers and jumps and corrected for atmospheric mass loading displacements. We corrected the resulting velocities for the elastic response of the solid Earth to global changes in ice sheets, glaciers, and ocean loading, as well as for changes in the Earth's rotational pole relative to the 20th century average. We then applied a spatial median filter to remove sites where local effects were dominant to leave approximately 4000 GPS sites. The resulting novel global GPS dataset shows a clean GIA signal at all post-processed stations and is suitable to investigate the behaviour of global GIA forward models. The results are transformed from a frame with its origin in the centre of mass of the total Earth's system (CM) into a frame with its origin in the centre of mass of the solid Earth (CE) before comparison with 13 global GIA forward model solutions, with best fits with Pur-6-VM5 and ICE-6G predictions. The largest discrepancies for all models were identified for Antarctica and Greenland, which may be due to either uncertain mantle rheology, ice loading history/magnitude and/or GPS errors.