Table 3.

Oxygen budget for SLW water column.

	Sources			Sinks					Annual O2 Deficit	Time until anoxia	Time since source
	Ice Melt	Inflow	Total Source	Water Auto	Water Hetero	Sediment Hetero	Sediment Methano	Total Sink
Moles O2 y−1	1.0 × 106	5.0 × 105	1.5 × 106	2.6 × 106	1.2 × 105	4.9 × 105	6.1 × 105	3.9 × 106	1.2 × 106	4	39
% of total sink or source	67	33	–	68	3	13	16	–	–	–	–

“Auto” refers to chemoautotrophy, “Hetero” refers to heterotrophy, “Methano” refers to methanotrophy. Sediment data are from the top 2 cm (Christner et al., 2014; Michaud, 2016). All “times” are in years. Annual oxygen deficit was computed by subtracting the total sinks from the sources. Time until anoxia was computed by dividing the measured oxygen concentration by the annual deficit. Time since source is the amount of time required to achieve the measured concentration of oxygen, starting at atmospheric equilibrium at standard temperature and pressure.