<P> This human dispersal left abundant traces along the coasts of the Atlantic Ocean . 50 ka - old, deeply stratified shell middens found in Ysterfontein on the western coast of South Africa are associated with the Middle Stone Age (MSA). The MSA population was small and dispersed and the rate of their reproduction and exploitation was less intense than those of later generations . While their middens resemble 12--11 ka - old Late Stone Age (LSA) middens found on every inhabited continent, the 50--45 ka - old Enkapune Ya Muto in Kenya probably represents the oldest traces of the first modern humans to disperse out of Africa . </P> <P> The same development can be seen in Europe . In La Riera Cave (23--13 ka) in Asturias, Spain, only some 26,600 molluscs were deposited over 10 ka . In contrast, 8--7 ka - old shell middens in Portugal, Denmark, and Brazil generated thousands of tons of debris and artefacts . The Ertebølle middens in Denmark, for example, accumulated 2,000 m (71,000 cu ft) of shell deposits representing some 50 million molluscs over only a thousand years . This intensification in the exploitation of marine resources has been described as accompanied by new technologies--such as boats, harpoons, and fish - hooks--because many caves found in the Mediterranean and on the European Atlantic coast have increased quantities of marine shells in their upper levels and reduced quantities in their lower . The earliest exploitation, however, took place on the now submerged shelves, and most settlements now excavated were then located several kilometers from these shelves . The reduced quantities of shells in the lower levels can represent the few shells that were exported inland . </P> <P> During the LGM the Laurentide Ice Sheet covered most of northern North America while Beringia connected Siberia to Alaska . In 1973 late U.S. geoscientist Paul S. Martin proposed a "blitzkrieg" colonization of America by which Clovis hunters migrated into North America around 13,000 years ago in a single wave through an ice - free corridor in the ice sheet and "spread southward explosively, briefly attaining a density sufficiently large to overkill much of their prey ." Others later proposed a "three - wave" migration over the Bering Land Bridge . These hypotheses remained the long - held view regarding the settlement of the Americas, a view challenged by more recent archaeological discoveries: the oldest archaeological sites in the Americas have been found in South America; sites in north - east Siberia report virtually no human presence there during the LGM; and most Clovis artefacts have been found in eastern North America along the Atlantic coast . Furthermore, colonisation models based on mtDNA, yDNA, and atDNA data respectively support neither the "blitzkrieg" nor the "three - wave" hypotheses but they also deliver mutually ambiguous results . Contradictory data from archaeology and genetics will most likely deliver future hypotheses that will, eventually, confirm each other . A proposed route across the Pacific to South America could explain early South American finds and another hypothesis proposes a northern path, through the Canadian Arctic and down the North American Atlantic coast . Early settlements across the Atlantic have been suggested by alternative theories, ranging from purely hypothetical to mostly disputed, including the Solutrean hypothesis and some of the Pre-Columbian trans - oceanic contact theories . </P> <P> The Norse settlement of the Faroe Islands and Iceland began during the 9th and 10th centuries . A settlement on Greenland was established before 1000 CE, but contact with it was lost in 1409 and it was finally abandoned during the early Little Ice Age . This setback was caused by a range of factors: an unsustainable economy resulted in erosion and denudation, while conflicts with the local Inuit resulted in the failure to adapt their Arctic technologies; a colder climate resulted in starvation; and the colony got economically marginalized as the Great Plague and Barbary pirates harvested its victims on Iceland in the 15th century . Iceland was initially settled 865--930 CE following a warm period when winter temperatures hovered around 2 ° C (36 ° F) which made farming favorable at high latitudes . This did not last, however, and temperatures quickly dropped; at 1080 CE summer temperatures had reached a maximum of 5 ° C (41 ° F). The Landnámabók (Book of Settlement) records disastrous famines during the first century of settlement--"men ate foxes and ravens" and "the old and helpless were killed and thrown over cliffs"--and by the early 1200s hay had to be abandoned for short - season crops such as barley . </P>

Where does the pacific in the atlantic ocean meet