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Fire frequency - this refers to the number of times fire occurs in a given area under a defined geologic time. The concept of fire frequency is often applied to local fire events. [25] Fire intensity - also known as fire severity or magnitude is the degree of fire or the magnitude of fire event. Fire intensity is categorized into low fire ...
The fossil record of fire first appears with the establishment of a land-based flora in the Middle Ordovician period, 9] permitting the accumulation of oxygen in the atmosphere as never before, as the new hordes of land plants pumped it out as a waste product.
The Conodont Alteration Index (CAI) is used to estimate the maximum temperature reached by a sedimentary rock using thermal alteration of conodont fossils. Conodonts in fossiliferous carbonates are prepared by dissolving the matrix with weak acid, since the conodonts are composed of apatite and thus do not dissolve as readily as carbonate.
The output section of the NFDRS structure chart is the components or simply the outputs that are based in fire behavior description but expressed in the broader context of fire danger rating. [ 6 ] Spread Component – Displays a value numerically equivalent to the predicted forward rate of spread of a head fire in feet per minute.
Tree core sample collected with an increment boarer A cat-face fire scar on a ponderosa pine A cross section of a ponderosa pine fire scar showing several dated fire events The growth record of a tree in seasonal climates is preserved in the growth rings in the stem wood; the field of dendrochronology is the study of the record of climate and ...
The base of the Sakmarian stage is laid with the first appearance of Streptognathodus postfusus in the fossil record. The top of the Sakmarian (the base of the Artinskian) is defined as the place in the stratigraphic record where fossils of Sweetognathus whitei and Mesogondolella bisselli first appear.
In the stratigraphy sub-discipline of geology, a Global Standard Stratigraphic Age, abbreviated GSSA, is a chronological reference point and criterion in the geologic record used to define the boundaries (an internationally sanctioned benchmark point) between different geological periods, epochs or ages on the overall geologic time scale in a chronostratigraphically useful rock layer.
Thick horizontal lines signify the existence of a fossil record for the respective time and taxa. Thin lines represent ghost lineages. A ghost lineage is a hypothesized ancestor in a species lineage that has left no fossil evidence, but can still be inferred to exist or have existed because of gaps in the fossil record or genomic evidence.