Jökull - 01.12.1972, Page 68

Fig. 1. Pliysiography of the eastern Greenland Sea (Johnson and Eckhoff, 1966) and residual
magnetic anomaly profiles across Knipovitch Ridge (Vogt, 1968). The broad black band at 74° N
is the index for Fig. 2.
Dashed line on the three magnetic profiles indicates location of trench crossing. Bjornoya Trench
is shown as a heavy black line on the eastern side of the Mid-Oceanic Ridge. Black circles
are earthquake epicenters from Sykes, 1965. Arrow indicates direction of spreading.
Mynd 1. Hafsbotn undir austurhluta Norðuríshafs (Johnsson og Eckhoff 1966) og frdvik segul-
sviðs á meelilinum pvert á Knipovitch-hrygg (Vogt 1968). Breitt svart band á 74° sýnir legu set-
þykktarmœlmgar í 2. mynd. Bjatrneyjar trog er sýnt sem breið svört lina á eystri hlið miðhafs-
hryggsins. Brotalina þvert á segullinur sýnir, hvar mœlilinur fóru yfir trogið. Ör sýnir áœtlaða
rekstefnu.
The adjacent trench (herein narned the
Bjornoya Trench) appears very similar to the
other deep ocean trenches with down-stepped
blocks on either wall, Ludwig et al., 1966) If
this supposition is correct, the Knipovitch
Ridge which is asymmetrically located in regard
to the Greenland ocean basin floor may have:
1. migrated eastward with time as has the
66 JÖKULL 22. ÁR
Mid-Oceanic Ridge ringing Antarctica (Le
Pichon, 1968);
2. throughout the history of the Greenland
Sea been located at tlie eastward edge of the
ocean basin with seafloor being destroyed in
the Bjornoya Trench;
3. sbifted axis eastward recently leaving a
buried relic axis in the central Greenland Sea