Quantification in Geophysics

How do phenomena become quantitative? When are we entitled to assign them numerical parameters and represent them by continuous mathematical functions? The paradigm cases of successful quantification are measurement procedures in laboratory physics: balances, precision clocks, thermometers, etc. Such measurements are undeniably quantitative, as well as demonstratively reliable and precise. Most areas of scientific research, however, lack the conditions afforded by the physical laboratory.

My project's bold thesis is that attempts at quantification often fail outside of physics because they draw from an unrepresentative set of examples within physics. In response, I propose to extend and refine such models by studying the historical development of quantitative measures in geophysics. Major geophysical phenomena were notoriously hard to quantify because (i) we cannot experimentally intervene in them directly, (ii) overlapping processes at a planetary scale complicate causal judgements, and (iii) much geophysical research is directly guided and constrained by concerns about human well-being. The project aims to understand the achievements and limits of quantification under such challenging conditions to inform broader debates about the prospects and limits of quantiative measurement.

Illustration of the Richter magnitude scale.