Europe to Britain. About 9000 years ago, that last divide was overtopped / dissected. Man was already resident in the area when these events happened. Since 7500 years ago the situation of tides, currents and land-forms has resembled the present. Rates of sea level rise dropped such that natural sedimentation by the Rhine and coastal processes widely compensate for transgression by the sea. In the southern North Sea, due to ongoing tectonic subsidence, the coastline and sea bed are sinking at the rate of about per century (1 meter or 39 inches in last 3000 years). About 7000–5000 BP, a general warming encouraged migration of all former ice-locked areas, including up the Danube and down the Rhine by peoples to the east. A sudden massive expansion of the Black Sea as the Mediterranean Sea burst into it through the Bosporus may have occurred about 7500 BP. Holocene delta At the beginning of the Holocene (~11,700 years ago), the Rhine occupied its Late-Glacial valley. As a meandering river, it reworked its ice-age floodplain. As sea-level rise continued in the Netherlands, the formation of the Holocene Rhine-Meuse delta began (~8,000 years ago). Coeval absolute sea-level rise and tectonic subsidence have strongly influenced delta evolution. Other factors of importance to the shape of the delta are the local tectonic activities of the Peel Boundary Fault, the substrate and geomorphology, as inherited from the Last Glacial period and the coastal-marine dynamics, such as barrier and tidal inlet formations. Since ~3000 yr BP (= years Before Present), human impact is seen in the delta. As a result of increasing land clearance (Bronze Age agriculture), in the upland areas (central Germany), the sediment load of the Rhine has strongly increased and delta growth has sped up. This has caused increased flooding and sedimentation, ending peat formation in the delta. In the geologically recent past the main process distributing sediment across the delta has been the shifting of river channels to new locations on the floodplain (termed avulsion). Over the past 6000 years, approximately 80 avulsions have occurred. Direct human impact in the delta began with the mining of peat for salt and fuel from Roman times onward. This was followed by embankment of the major distributaries and damming of minor distributaries, which took place in the 11–13th century AD. Thereafter, canals were dug, bends were straightened and groynes were built to prevent the river's channels from