Table 1.

The Observed Area, Mean Accumulation Rate, Estimated Snowfall Variability, Average Elevation Rate, and Average Mass Balance of AIS Drainage Basins Between May 1992 and May 2017

Drainage basin	Area (km2)	Mean ice accumulation rate (cm/year)	Snowfall variability (cm/year)	Elevation rate (cm/year)	Average mass balance (Gt/year)
1	465,525	29	4.2	3.1 ± 0.3	5.7 ± 2.1
2	741,575	7	1.6	0.3 ± 2.3	0.7 ± 6.2
3	1,501,700	5	0.4	0.7 ± 0.1	3.6 ± 0.6
4	239,475	22	3.2	3.3 ± 0.4	3.1 ± 0.6
5	184,750	21	4.3	4.4 ± 0.6	3.2 ± 0.6
6	599,025	13	1.4	1.8 ± 0.3	4.1 ± 0.8
7	493,875	18	2.3	1.6 ± 0.3	3.3 ± 0.9
8	162,250	23	4.7	4.1 ± 0.4	2.7 ± 0.5
9	145,725	15	3.1	3.0 ± 0.7	1.7 ± 0.5
10	893,375	5	0.4	0.0 ± 0.2	0.0 ± 0.8
11	252,625	7	1	0.4 ± 0.4	0.3 ± 0.4
12	722,525	23	2.1	1.8 ± 0.4	5.6 ± 1.3
13	1,108,875	23	2.1	−0.7 ± 0.4	−8.2 ± 2.0
14	711,675	21	2.1	−1.5 ± 0.2	−4.7 ± 1.0
15	123,675	25	5.3	−6.2 ± 1.5	−2.9 ± 0.8
16	258,825	5	0.8	−0.1 ± 0.3	−0.1 ± 0.3
17	1,769,850	5	0.3	0.3 ± 0.1	2.9 ± 0.8
18	253,975	13	3.4	3.9 ± 0.7	9.3 ± 1.5
19	358,525	14	1.6	−2.1 ± 0.3	−1.6 ± 0.8
20	177,625	79	12.9	−11.6 ± 1.0	−16.4 ± 4.0
21	210,600	56	8.5	−27.2 ± 0.7	−46.1 ± 7.2
22	208,025	43	6.4	−17.2 ± 0.8	−28.4 ± 6.2
23	73,925	99	18.9	−2.9 ± 1.3	−4.3 ± 2.1
24	99,525	92	17.1	5.1 ± 1.8	0.2 ± 1.5
25	35,425	202	40.5	−1.7 ± 2.9	−1.5 ± 1.3
26	41,500	109	23.4	5.4 ± 5.2
27	51,275	44	7.9	−2.0 ± 2.3
EAIS	9,909,800	12	0.5	0.6 ± 0.1	16.3 ± 5.5
WAIS	1,748,200	37	2.8	−5.6 ± 0.3	−81.9 ± 12.1
AP	227,725	101	16.6	2.7 ± 2.0

Note. Basins with regions of identified ice dynamical imbalance are italicized, and where elevation changes also exceed expected snowfall variability are in bold. AIS = Antarctic Ice Sheet; EAIS = East AIS; WAIS = West AIS; AAntarctic Peninsula.