Current global warming necessitates a detailed understanding of the relationships between climate and global ice volume. Highly resolved and continuous sea-level records are essential for quantifying ice-volume changes. However, an unbiased study of the timing of past ice-volume changes, relative to polar climate change, has so far been impossible because available sea-level records either were dated by using orbital tuning or ice-core timescales, or were discontinuous in time. Here we present an independent dating of a continuous, high-resolution sea-level record in millennial-scale detail throughout the past 150,000 years. We find that the timing of ice-volume fluctuations agrees well with that of variations in Antarctic climate and especially Greenland climate. Amplitudes of ice-volume fluctuations more closely match Antarctic (rather than Greenland) climate changes. Polar climate and ice-volume changes, and their rates of change, are found to covary within centennial response times. Finally, rates of sea-level rise reached at least 1.2 m per century during all major episodes of ice-volume reduction.

Marked changes in human dispersal and development during the Middle to Upper Paleolithic transition have been attributed to massive volcanic eruption and/or severe climatic deterioration. We test this concept using records of volcanic ash layers of the Campanian Ignimbrite eruption dated to ca. 40,000 y ago (40 ka B.P.). The distribution of the Campanian Ignimbrite has been enhanced by the discovery of cryptotephra deposits (volcanic ash layers that are not visible to the naked eye) in archaeological cave sequences. They enable us to synchronize archaeological and paleoclimatic records through the period of transition from Neanderthal to the earliest anatomically modern human populations in Europe. Our results confirm that the combined effects of a major volcanic eruption and severe climatic cooling failed to have lasting impacts on Neanderthals or early modern humans in Europe. We infer that modern humans proved a greater competitive threat to indigenous populations than natural disasters.

No abstract

No abstract

Sea-level change is thought to influence the frequencies of volcanic eruptions on glacial to interglacial timescales. However, the underlying physical processes and their importance relative to other influences (e.g. magma recharge rates), remain poorly understood. Here we compare a ~360 kyr long record of effusive and explosive eruptions from the flooded caldera volcano at Santorini (Greece) with a high resolution sea-level record spanning the last four glacial-interglacial cycles. Numerical modelling shows that when the sea level falls by 40 m below the present-day level, the induced tensile stresses in the roof of the magma chamber of Santorini trigger dyke injections. As the sea-level continues to fall to -70 or -80 m, the induced tensile stress spreads throughout the roof so that some dykes reach the surface to feed eruptions. Similarly, the volcanic activity gradually disappears after the sea-level rises above -40 m. Synchronising Santorini's stratigraphy with the sealevel record by using tephra layers in marine sediment cores shows that 208 out of 211 eruptions (both effusive and explosive) occurred during periods constrained by sea level falls (below -40m) and subsequent rises, suggesting a strong absolute sea-level control on the timing of eruptions on Santorini -a result that probably applies to many other volcanic islands around the world. Climate as a Driver of VolcanismThe climate system's influence on solid-earth processes, including volcanic and tectonic activity 1-4 is receiving increasing attention from researchers. Changes in surface loading by growth and retreat of ice-sheets have been linked to changes in volcanic activity in formerly glaciated areas on timescales from 10 3 -10 6 years [5][6][7][8][9][10][11] . Removal of an ice-sheet reduces the overburden pressure and results in additional decompression melting in the mantle. The associated stress changes in the crust facilitate dyke propagation to the surface, thereby increasing volcanic activity 10 . The effects of concomitant sealevel changes on volcanic activity, however, have not yet been firmly established. Because sea-level