Table 2. Energy balance model parameter values.

Parameter	Description	Laboratory value	Antarctic value
ki	Thermal conductivity of ice (W K−1 m−1)	2.22	2.07
kw	Thermal conductivity of water (W K−1 m−1)	0.58	0.58
km	Thermal conductivity of meteorite (W K−1 m−1)	1.5, 25	1.5, 25
ca	Heat capacity of air (J kg−1 K−1)	1,005	1,005
ρa	Air density (J kg−1 K−1)	1.29	0.95
ρi	Density of ice (kg m−3)	916.2	916.2
Lm	Latent heat of melting ice (J kg−1)	3.34 × 105	3.34 × 105
Lv	Latent heat vapourization, water (J kg−1)	22.6 × 105	22.6 × 105
γi	Attenuation coefficient of blue ice (m−1)	2.5	2.5
γw	Attenuation coefficient of water (m−1)	0.001	0.001
V	Ice sheet heave velocity (metres per year)	—	0.065
v	Ice sheet sublimation rate (metres per year)	Negligible	V/2
αi	Blue-ice albedo (−)	0.62	0.62
αm	Meteorite exterior-surface albedo (−)	0.106–0.159	0.13
σ	Stefan–Boltzmann's constant (W m−2 K−2)	5.667 × 10−8	5.667 × 10−8
	Emmissivity of ice (−)	0.94	0.94
θ	Solar elevation angle (°)	90	Computed
Ta	Air temperature (°C)	−1
	Lowest air temperature (°C)	—	−40
Snet	Incoming shortwave energy (W m−2)	1,440	Fig. 4
Qlong	Incident longwave radiation (W m−2)	300
	Longwave energy parameter (W m−2)	—	93
	Longwave energy parameter (W m−2)	—	47.5
	Average wind speed (m s−1)	2	11
u*	Friction velocity (m s−1)	0.1	0.1
T∞	Ice temperature at bottom (°C)	−4	—
z∞	Ice depth (m)	0.05	—
ϕ	Heat flux in region 4 (W m−2)	—	0
sh	Solar shading	0	7.5%
w	Meteorite width (m)	0.01	0.03

Parameter values used in our energy balance model, for both the laboratory study and the Antarctic analogy (based on the Frontier Mountain meteorite trap area; see the Methods section).