They are referring to
http://earthquake.usgs.gov/regional/...al_mag_big.php
So, the data sorted from this page would show the given graph at
http://www.thehorizonproject.com/earthquakes.cfm
See here:
|number of earthquakes M 6-9|year|
1 1556
1 1619
1 1663
1 1664
1 1668
1 1687
1 1693
1 1700
1 1730
1 1755
1 1787
1 1811
5 1812
1 1821
1 1823
1 1835
1 1836
1 1838
2 1843
1 1855
2 1857
1 1865
4 1868
1 1871
2 1872
1 1873
1 1875
1 1877
1 1882
1 1886
2 1887
1 1890
1 1891
3 1892
1 1895
1 1896
2 1897
2 1898
6 1899
1 1900
2 1901
2 1902
2 1903
2 1904
3 1905
4 1906
3 1907
3 1908
1 1909
4 1910
4 1911
2 1912
1 1914
3 1915
1 1917
4 1918
3 1920
3 1922
4 1923
4 1925
1 1926
4 1927
1 1928
5 1929
2 1930
4 1931
5 1932
4 1933
5 1934
6 1935
1 1937
3 1938
2 1939
3 1940
1 1941
4 1942
4 1943
4 1944
2 1945
6 1946
4 1947
4 1948
5 1949
2 1950
3 1951
2 1952
5 1953
8 1954
12 1957
4 1958
4 1959
3 1960
3 1962
2 1963
4 1964
13 1965
6 1966
3 1967
6 1968
4 1969
5 1970
4 1971
6 1972
1 1973
5 1974
6 1975
6 1976
2 1977
2 1978
2 1979
5 1980
3 1981
1 1982
4 1983
1 1984
4 1985
3 1986
4 1987
4 1988
2 1989
2 1990
3 1991
6 1992
3 1993
3 1994
4 1995
1 1996
5 1997
8 1998
13 1999
6 2000
7 2001
23 2002
39 2003
35 2004
35 2005
25 2006
47 2007
34 2008
WT