earthquakes_underdispersion.R

library(tidyverse)
library(lubridate)
quakes_raw <- read_csv("https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.csv")

quakes <- quakes_raw %>% mutate(hour = floor_date(time, "hour"),
                                day = floor_date(time, "day"))

quake_fanos <- quakes %>% group_by(hour, day, net) %>%
  summarise(count = n()) %>%
  group_by(day, net) %>%
  summarise(fano = var(count) / mean(count))  %>%
  filter(!is.na(fano))

max_fano <- max(quake_fanos$fano)
quake_fanos %>%
  ggplot(aes(x = fano)) + geom_histogram(breaks = seq(0, max_fano, by = 0.5)) +
    geom_vline(xintercept = 1, color = "blue", size = 1) + 
  facet_wrap(~net)