Loss Estimation Terminology for Earthquake Property Assessments – Does your building need a seismic retrofit?
Probable Loss (PL): Earthquake loss to the building systems that has a specified probability of being exceeded in a specific time period.
Scenario Loss (SL): Earthquake loss to the building systems associated with specified earthquake events (probabilistic return period or earthquake of specified size and location) on specific fault(s) affecting the building.
Scenario Expected Loss (SEL): Defined as the expected value of the Scenario Loss (SL) resulting from the specific earthquake ground motion of the earthquake scenario selected. SEL is defined as the expected or mean loss resulting from the damage experienced due to a 475-year return period earthquake. SEL has an approximate 50% possibility of exceedance. The SEL is sometimes referred to as the PML50. PML – Probably Maximum Loss
Scenario Upper Loss (SUL): Defined as the Scenario Loss (SL) that has a 10% probability of exceedance due to the specified earthquake ground motion of the scenario considered. It is also referred to as the 90% non-exceedance probability or the upper-bound loss. The most common representation of the SUL is the SUL475, associated with the 90% confidence loss estimation resulting from the damage experienced due to a 475-year return period earthquake. The SUL is sometimes referred to as the PML90. PML – Probably Maximum Loss
For a complete explanation of PML-SEL-SUL, http://saundersseismic.com/wp-content/uploads/2020/05/PML-SEL-SUL.pdf