File name: Narwhal_in_pack_ice_OE_720.jpg Original Resolution (pixels): 720 × 400 File Size: 187 KB (MIME Type: image/jpeg) Date Published: February 27, 2013 Alternate Text: Narwhal up for air View image full size Download file Image caption A narwhal emerges for a breath in a lead, or crack, in the pack ice.