In the question, Weapons for a civilisation-destroying giant robot, I asked about what weapons might be mounted on a giant snakebot over 1 km in diameter and over 9km long, equipped with six fusion reactors. It was mentioned in one of the answers that it might be noticed - even in Antarctica - that something this big was being built.
The snakebot is being built by a large number of self-replicating engineering nanobots powered for the most part by the mineral reserves of the continent as well as fusion power from the snakebot's reactors as construction progresses.
The engineering nanites were delivered by a ballistic-descent module with a total volume of around 100 liters and massing about 250kg. The module provides power for initial nanite replication and resource location, during which time the nanites build their own additional power supplies.
Construction is taking place under the thickest portion of the East Antarctic ice-cap, beneath 2-3 kilometres of ice. No significant change in the elevation of the surface ice will take place.
The nanites and their power supplies are highly efficient, and they are exercising heat-management procedures that spread the heat generated by their activities over an area of well over a hundred square kilometres of the antarctic ice cap centred over the construction site, as well as lower levels of temperature rise over a much wider area where the nanites are mining for resources.
The detectable signs of construction might be a rise in the temperature of the surface ice by a few degrees over a large area, as well as an increase in the rate of ice flow toward the edge of the ice sheet, plus the fact that there is a huge metal object being constructed deep under the ice.
Construction will take place over eight years, plus or minus two years, and heat production will rise steadily to its maximum level over the first third of the construction time, and will only fall off slightly when construction is completed and the snakebot begins to move.
We can assume that if the delivery package was observed in its ballistic descent, it would appear to be a meteorite of a size that wouldn't warrant investigation in an area as remote and inhospitable as central Antarctica.
Am I correct in assuming that the arrival of the delivery package would not be investigated?
What is the liklihood that construction of the snakebot would be noticed by humans, even if it is not known what is causing the observed changes? What changes might be observed first?
What response might be mustered by humans to investigate the observed changes in Antarctica? How long might it take to begin investigating, how long could such an investigation be expected to take, and what personnel would respond?
Is it possible for humans to conclude that a giant robot is being built by nanites (that are reasonably intelligent and self-destruct if captured, and so aren't likely to be directly observed) within the 6-10 year timespan that construction will take?
If it is concluded by the investigators that a giant robot is being constructed before such time as the robot is completed, what response might be mustered and how long would that response take?