Explain why member firms of a cartel like opec have incentives to agree to a low cartel production level and then produce more than its quota.

Because the members of OPEC are dealing with oils as their main selling commodities.

The thing is, oil is an un-renewable natural resources , well not unnecessarily un-renewable, but it took hundred of millions of years for earth to produce a new oil.

So the OPEC members have to be really careful in maintaining their quota. And also, if they produce more, the price of the oils will drop.

In line with other previous and contemporaneous proposals, in 1912 the meteorologist  alfred wegener  amply described what he called continental drift, expanded in his 1915 book the origin of continents and oceans and the scientific debate started that would end up fifty years later in the theory of plate tectonics.