We have begun experimenting with Spark and would like to replace some apex we have with the new api features to record user location?

There is very little in the documentation - I found 

“Refresh user location”

Refreshes the location merge variables to reflect the user’s current location.

and I found some merge variables listed for user address.

Can anyone explain how we trigger the refresh user location “action” and if we can store latitude and longitude when this is triggered?

Merry Xmas all