Dining room jarrah table crack

Good afternoon, any advice relative to the following much appreciated


Dining table purchased new Dec 1998, has not displayed any warping/issues until Feb 2021, some 22+ years


Table is some 2300mm x 1600mm, with crack now indicated on top surface and being some 1900mm long and 1mm wide


With straight edge applied across the table it is clearly evident table top has bowed upwards at central length joint and by some 1 – 2mm at end of straight edge


Two questions come to mind, one being why did this now evident effect occur as there has been no specific environmental change for many years, second how to rectify the cause and/or crack

Thanks in advance

Perhaps it had a 22 year warranty...
:D

One of those things I suppose -Once made things from mount Dandynong Wet place at the best.Was always worried about shrinkage.

Photo 5 looks to me like the glue joint has let go.

As Pete57 has said, its the joint that has let go rather than a crack. Looking at the join from under the table, is it closed up tight?
How is the top attached to the apron? Has the underneath been coated with finish?
If it’s firmly fixed then there hadn’t been allowance for expansion which is probably why it let go at the join.
A rectification method will be helped by answers to the above IMHO.

A photo of the underside showing both the joint and the general construction would help decide the best method for rectification.

The glue has let go. Pull it apart, use hot water to loosen it if necessary, clean off the old glue, and reglue with epoxy or similar. Then you may have to refinish the top before reassembling.