We can consider the dirgible flight of Roald Amudsen in May of 1926.
Amudsen passed over the pole and then steered a course along 170*
longitude West towards the Bering Straits between Alaska and Siberia.
He experienced a couple of the usual polar anomalies the farther
North he went: Warming of the air and sea temperatures was one of
them, and the presence of land birds too far away from any land.
But what is interesting to our current analysis is the fact that when the
Amudsen dirgible reached the Bering Straits it ended up over 100
miles off course on the Russian side. This suggests that the dirgible
dipped into and followed along the bowl-like depression, and that the
irregular curvature threw it off course and sent it into Siberia on a
slight tangent. All of the above evidence suggests a polar opening,
on the Siberian side of the Pole.
If he flew over the supposed Pole, then he was very close to the opening.
What a shame!