What are caves and karst

and why do they matter?

Although definitions vary, we generally use the term

“cave” to refer to natural (not man-made) passages into

the underground that are large enough to permit

human access and are deep enough that natural light

from the entrance(s) does not penetrate throughout.

“Karst” is the integrated three-dimensional landscape of

sinkholes, caves and springs that develops in soluble

bedrocks, mostly – but not exclusively - limestones.

Karst covers 12–15% of the Earth’s terrestrial surface and,

in Canada, accounts for approximately 900,000 km

2

of

the ice-free land mass.

Importantly, karst resources benefit billions of people

around the globe. While best known for exciting cave

systems, karst is associated with many important

natural and cultural values, rare biota in both surface

and subsurface habitats, and groundwater aquifers that

provide about 10–20% of the planet’s population with

fresh drinking water. Karst landscapes provide refuge

for endangered and endemic species, including bats,

and some have special significance to First Nations.

Certain caves are also proving to be an invaluable place

for the scientific study of long-term climate change that

may prove to be of medicinal or other value.

Less tangible, but no less important – many caves are

places of amazing beauty, sounds, and opportunities for

exploration and fun physical adventure for those with

appropriate training, equipment and fitness.

Did you know? 2022 was the International Year of Caves

& Karst