SEISMERIO

This tool builds one candidate rupture scenario per fault system from a set of trench paleoearthquake ages (TPAs) using a sweep-line approach adapted from the classical geometric algorithm for reporting interval intersections (Bentley & Ottmann (1979)). Instead of segments in a plane, the "intervals" here are each trench's dated event windows (older/younger bound); the sweep advances from the oldest active bound to the youngest, and at each step looks for the largest set of trenches whose current TPA windows overlap. That overlap becomes a candidate fault event age (FEA), following the rule-based reconstruction scheme of Lombardi et al. (2026), the paper describing the official POPE software package this tool reimplements.

Three rules keep the reconstruction consistent: every TPA must eventually be assigned to some FEA (R1); each TPA can define at most one FEA (R2), so once a trench's oldest active event has been consumed by a bound it touches, the sweep advances to that trench's next event; and two TPAs from the same trench can never be forced into the same FEA (R3), since a single trench cannot record two separate ruptures as if they were one earthquake. After the sweep completes, any FEAs left temporally overlapping are merged in a consolidation pass — but only when the merge would not itself violate R3 — following the same general chronology-modeling logic used to reconstruct regional earthquake recurrence and "earthquake storm" sequences from paleoseismic trench data (Cinti et al. (2021)).

The official POPE package enumerates every rupture scenario consistent with the input data for expert review and probabilistic assessment of future fault behavior (Lombardi et al. (2025)); this browser tool instead computes a single self-consistent candidate scenario per fault — useful for a quick first look at a dataset before turning to the full package for exhaustive, citable scenario enumeration.

The descriptive CSV format has one row per trench event. Column order is flexible (columns are matched by keyword, not position), but here is a real example row from the Arava dataset so you can see what belongs in each column:

Fault System

Numeric ID grouping trenches into the same fault — every trench sharing a Fault System number is analyzed together as one fault when building chronograms and scenarios.

Trench No.

Numeric ID for the trench site within its fault system. See the geographic-ordering note below.

Fault System Name

Descriptive name of the fault (e.g. "Arava Fault 3") — used for chart titles and section headings.

Trench Name

Descriptive name of the trench site (e.g. "Qatar") — used for row labels on the chronograms.

POPE Event Position

The event's position within this trench's stratigraphic column: 1 = the youngest (most recent) event at that trench, increasing with age — this matches POPE's own convention.

Original Event Name

The event's original label from the source paleoseismic study (e.g. "E4", "EQIII") — shown in table rows and chart labels alongside the trench name.

POPE Older Bound

The older age bound in years, using this tool's signed convention (negative = BCE, positive = CE). Leave blank for an unconstrained older bound (treated as open-ended / unknown).

POPE Younger Bound

The younger (more recent) age bound in years, same signed convention. Leave blank for an unconstrained younger bound (treated as "present").

Ordering Trench No. geographically: assign Trench No. values in geographic order/procession along the fault trace — for example, the northernmost trench as 1, then increasing sequentially as you move south along the fault (or vice versa) — rather than in an arbitrary order of data collection. This keeps trenches presented in a spatially sensible sequence throughout the tool's tables and chronograms.

Fault System numbering does not need to be consecutive: if you have no paleoseismic data for a given fault segment, simply omit that Fault System number from the file entirely. The tool only ever builds sections for the Fault System numbers that actually appear in your data — a missing number (e.g. going 1, 2, 4, 5, 6 with no 3) is not treated as an error and does not produce an empty section.