Circumcision Harbor
After turning north from Detaille Island during the afternoon of December 23 the Endeavour headed across the open waters of the Bellingshausen Sea and encountered substantial swell from a storm far away in the Drake Passage. The swell built to waves of up to 6 meters by early morning as the Endeavour continued northward toward the more sheltered waters of French Strait. By noon, a group of small rocky islands south of Lemaire Channel afforded considerable protection from waves and we had calmer waters during lunch.
The afternoon brought high clouds, calm winds, and warm temperatures as we anchored in Circumcision Harbor on Petermann Island. We took the Zodiacs to shore for an afternoon of examining penguin colonies, and beautifully glaciated exposures of granodiorite along the shoreline and at the tops of snow covered hills. Petermann Island is historically important because French explorer Jean-Baptiste Charcot over-wintered there in 1909. However, no evidence of this was visible due to deep snow.
Granodiorite exposed on Petermann Island comprises the roots of the Mesozoic magmatic arc that once extended in a continuous curve from the west coast of South America to South Georgia and the Antarctic Peninsula. The magma that crystallized beneath the surface included numerous dark xenoliths of country rock, one of which can be seen in the left foreground. Subsequently, planar black intrusions of basaltic magma filled fractures across through the granodiorite. Long after solidification and cooling of the igneous rocks, glaciers carved the wonderfully curved and elongate low hummocks and hills seen in the photo.
After turning north from Detaille Island during the afternoon of December 23 the Endeavour headed across the open waters of the Bellingshausen Sea and encountered substantial swell from a storm far away in the Drake Passage. The swell built to waves of up to 6 meters by early morning as the Endeavour continued northward toward the more sheltered waters of French Strait. By noon, a group of small rocky islands south of Lemaire Channel afforded considerable protection from waves and we had calmer waters during lunch.
The afternoon brought high clouds, calm winds, and warm temperatures as we anchored in Circumcision Harbor on Petermann Island. We took the Zodiacs to shore for an afternoon of examining penguin colonies, and beautifully glaciated exposures of granodiorite along the shoreline and at the tops of snow covered hills. Petermann Island is historically important because French explorer Jean-Baptiste Charcot over-wintered there in 1909. However, no evidence of this was visible due to deep snow.
Granodiorite exposed on Petermann Island comprises the roots of the Mesozoic magmatic arc that once extended in a continuous curve from the west coast of South America to South Georgia and the Antarctic Peninsula. The magma that crystallized beneath the surface included numerous dark xenoliths of country rock, one of which can be seen in the left foreground. Subsequently, planar black intrusions of basaltic magma filled fractures across through the granodiorite. Long after solidification and cooling of the igneous rocks, glaciers carved the wonderfully curved and elongate low hummocks and hills seen in the photo.
