Cumulative curves of the number of eruptions normalised to the number of recorded events prior to 1 ka (Figure 5) enables quantification of the decline in under-recording by comparison with recording rate.
These statements, which are formally about the global recording rate, apply, approximately, to the average recording rate across volcanoes (Section "Definition of the recording rate").
represents the half-life period of recording rate R t).
The notion of a 'global recording rate' is imprecise.
We provide a definition which highlights the difference between the global recording rate and the mean recording rate across volcanoes.
This paper provides an empirical analysis of the global recording rate of large eruptions of stratovolcanoes; the definition of the global recording rate is discussed and clarified in Section "Definition of the recording rate".
This distinction between the global recording rate and the mean recording rate is an important part of the definition and interpretation of the global recording rate, but whether it really matters is moot.
In general, though, (2a) shows that the global recording rate is biased away from the mean recording rate towards the recording rates of the most active volcanoes.
This approach imposes minimal structure on the shape of the recording rate through time.
Fig. 4 Residuals between the observed recording rate and fitted functions.
Let the most recent period, period k say, have a recording rate of π k =1.
