A series of explosive phases and
upheaval of land mass characterize this period. After a period
of quiescence of only 11 years, the volcano awoke once again.
Early in May 1939, it was observed that the waters in the
little bay of Agios Georgios with its chapel, were heating
up, and the coastline was subsiding. A submarine explosion
at the harbour entrance on August 20th cleared the vent for
the new magma which began to appear, creating a small dome
which the volcanologists of the time baptized 'Triton'.
One month later, the focus of volcanic activity shifted a
few hundred meters to the northeast where it created lava
flows and a dome which were given the name of 'Ktenas' after
Greek geologist who studied the Kameni eruptions.
This lava filled the little harbour of Agios Georgios and
covered the Triton dome. Between November 1939 and July 1940,
the volcanic activity shifted even farther to the northeast,
creating the Fouque lava flows and dome, named after the French
naturalist who studied Santorini and the eruptions of Kameni
up until 1866.
In July 1940 two new centers of activity appeared to the
south of the Fouque center. The first was called Smith, after
an American and the second Reck, after a German volcanologist,
both of whom had studied the 1925 eruptions. These centers
produced lava domes and flows which covered the western slopes
of the now single island of Nea Kameni and flowed into the
sea. The explosive activity of this period was not severe,
and the height to which volcanic ash was ejected did not exceed
Late in August 1940, two major explosions from the summit
of the island blew the old rock plug from 1866 into the air,
opening two large craters each 50 meters across. These are
the craters which visitors to the island go to see today.
There was no magma outflow from these craters. Towards the
end of November of that same year, viscous lava began to flow
from a vent a bare 100 meters to the east, creating the lava
fields named 'Niki' (Victory), in honour of the Greek victories
in Albania. The lava covered the eastern slopes of the island,
stopping just short of the sea.
This eruptive cycle came to an end in July 1941.