smog-like air pollution caused by volcanic gases and particulates (R1)
Visual strip-transect search
a research method for studying fish in which two divers swim side-by-side down either side of a transect, counting all fishes seen within a specified corridor (M4)
Viscosity
fluidity (A1)
Viable
able to germinate (as a seed) or hatch (as an egg) (C2)
Vesicle
a hole left behind when lava cools quickly and traps gases (A1)
Vertebrate
an animal with a backbone (C4)
Unicolonial
an ant behavior strategy in which ants of the same species form large colonies of many different nests (A4)
Ungulate
hoofed mammal (IS1)
Under-rock survey
a research technique in which researchers lift rocks and catalogue the invertebrates they find there (A4)
Tropopause
the boundary between the atmospheric layers troposphere and stratosphere where the drop in temperature with increasing altitude ceases (A2)