It's not actually closed, just delays as it's down to one line. From National Rail Enquiries.....Recent poor weather conditions have caused a landslip near Appleby. Work is ongoing to stabilise the landslip and repair damage to the track.
While this work is taking place, one of the two lines has had to be closed resulting in a reduced train service between Carlisle and Leeds. Some buses are also running between Carlisle and Appleby, extending journey times by up to 60 minutes.
A full service is not expected to resume until at least the end of February.