The last photograph was taken on Half Moon Island in Antarctica. It is an iPhone XS shot, my camera equipment was in my backpack and I was hurrying to catch the zodiac from the beach. The phone was on as it was being used as a GPS logger. I am impressed with the quality of the iPhone camera, certainly for close subjects.
The first three photos were taken at Deception Island, a volcanic island in Antarctica. The name probably comes from the fact that it looks like a normal island, but is in fact a ring around a flooded caldera. The caldera is 9km (5.6 miles) by 6km (3.7 miles). The last major volcanic eruptions were in 1967, a969 and 1970, which destroyed the scientific research stations. The whaling industry had disappeared in the 1930s.