Authorization: Aerial Survey Window, Putorana Plateau Sector 4

FROM:

M. Ostroff, Branch Chief, GSC-2

TO:

Desk Analyst, North Eurasia Watch (NEW-3)

CC:

Aviation Liaison (AL-1); Records, GSC-2

RE:

Authorization — Aerial Survey Window, Putorana Plateau, Krasnoyarsk Krai. Operation reference PUTORANA-MARCH-11.

This memo authorizes a single (1) overflight window for high-resolution magnetometer and LWIR survey of the Putorana Plateau, Sector 4 (lat. 69.1–69.4 N, lon. 94.2–95.0 E), in support of standing geophysical baseline maintenance under the Siberian Traps Province monitoring program.

Standing constraints (reaffirmed)

1. No flight track shall pass within 18 km lateral of the basalt vent field designated PT-4-V. Re-route through 94.8 E corridor.
2. No personnel shall be on the surface inside Sector 4 for the duration of the window, nor for 72 hours following. Coordinate with Norilsk Met Service cover story (atmospheric sampling, routine).
3. In the event of unscheduled atmospheric chemistry returns (SO₂ > 4 ppm at altitude, or any detection of the marker compound listed in Annex C), the aircraft shall execute the standard ascending right-hand departure and report only by encrypted post-flight channel. No in-flight voice traffic regarding the return.

Reminder

Sector 4 remains under the 252-Ma legacy chemistry advisory. The plateau is not, repeat not, to be characterized in any outward-facing product as “active.” All public-facing geological language remains “stable Triassic flood basalt province, dormant since end-Permian.”

Authorization expires automatically at window close. No extensions granted at branch level; escalate to GSC-1 for any deviation request.

M. Ostroff Branch Chief, GSC-2 11 February 2026

Annexes: A (flight plan), B (cover-story coordination), C (marker compound list — SCI only, request separately)