Hier volgt het aardbevingenverhaal van 2 jaar geleden van Jacques Hagoort. Inclusief sappige details over de poortwachters van de aardbevingswetenschap in Nederland.
Hij komt in zijn stuk ‘Empirical Model for Induced Earthquakes in the Groningen Gas Field’ tot de volgende conclusies.
1. The observed cumulative number of earthquakes with a magnitude greater than 1,5 correlates very well with cumulative gas production and can be very well described mathematically by a quadratic equation.
2. The quadratic equation can be used to predict the average yearly earthquake frequency for a given production rate profile. Observed yearly frequencies deviate substantially from the predicted frequencies, indicating a sizeable inherent natural variability.
3. The strength distribution of the earthquakes is fairly well described by the Gutenberg-Richter equation for cumulative frequency as a function of magnitude. For all practical purposes this distribution is time-invariant.
4. The observed increase in stronger earthquakes in the course of time can be attributed to an increase in yearly earthquake frequency.
5. The ultimate number of earthquakes with a magnitude greater than 1,5 over the entire life cycle of the field is of the order of 700. This number is not affected by yearly production rate: a lower/higher production rate simply means that the total number of earthquakes is spread out over a longer/shorter time period.
6. Up to 01-01-2017 roughly 300 earthquakes with a magnitude greater than 1,5 have been recorded, leaving 400 earthquakes for the remaining production period.
7. The magnitude of the strongest future earthquake is estimated at 4,4 on the Richter scale.
8. Example forecasts are presented that highlight how yearly production rate affects the development of seismicity in Groningen.
Jacques Hagoort: Formerly Professor of Reservoir Engineering – Delft University of Technology
Download bestand: Empirical Model for Induced Earthquakes in the Groningen Gas Field
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