title: Multi-day radon signals with a radioactive decay limb -- occurrence and geophysical significance.
abstract: Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geogas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn, (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes.
authors.affiliation: Geological Survey of Israel, Jerusalem, Israel. steinitz@mail.gsi.gov.il
authors.forename: G
authors.initials: G
authors.lastname: Steinitz
authors.forename: M C
authors.initials: MC
authors.lastname: Martín
authors.forename: N
authors.initials: N
authors.lastname: Gazit-Yaari
authors.forename: M L
authors.initials: ML
authors.lastname: Quesada
authors.forename: J
authors.initials: J
authors.lastname: de la Nuez
authors.forename: R
authors.initials: R
authors.lastname: Casillas
authors.forename: U
authors.initials: U
authors.lastname: Malik
authors.forename: Z B
authors.initials: ZB
authors.lastname: Begin