Table 2 Locations and peak and average CH4 EC sea-air CH4 fluxes from Laptev Sea and East Siberian Sea seep areas sampled during SWERUS-C3.

2σ error is ±2 mg m−2 day−1 for peak (single measurement) flux observations. Areal extent of each seep area is determined by the distance from peak flux of first measurement <6 mg m−2 day−1 CH4, a very conservative assumption that seep area extends this distance from peak. EC measurement locations refer to discrete measurement locations in the spatially normalized dataset, not the total number of EC measurements. All data are after filtering. LS1, LS2, ESS1, ESS2, and ESS7 are displayed in Fig. 2.

latitude (°N)
Peak longitude (°E)Peak CH4 flux
(mg m−2 day−1)
Average CH4 flux
(mg m−2 day−1)
Estimated areal extent
of fluxes >6 mg m−2
day−1 (km2)
EC measurement
locations within
enhanced area
76.7742 (LS1)125.833117036.02.025
76.8884 (LS2)127.776233.114.84.47
74.9571 (ESS1)161.08396181429.44
74.9913 (ESS2)161.142311429.618.87
74.9099 (ESS3)160.424654.243.46.32
74.4200 (ESS4)166.930311.811.80.51
74.4376 (ESS5)167.343917.617.65.41
73.8477 (ESS6)170.383017.217.23.91
74.1982 (ESS7)171.39232212213.01
Area weighted fluxes
  Laptev Sea seep areas21.46.432
  East Siberian Sea seep areas63.347.317