The beginning of the amazing events at Krakatoa in 1883 date to May 20 when there were initial rumblings and venting from the volcano, which had been dormant for about 200 years.
A refinery margin is the revenue associated with refining petroleum, expressed as a value per volume (e.g. $/L), net of the cost of the crude oil input. The simplest refining
In the second stage, supply and demand fundamentals stabilize resulting in a compression of refining margins. With lower crude prices, there is a general compression of most refining products spreads and differentials.