title: La Palma Earthquakes author:
- name: Steve Purves
orcid: 0000-0002-0760-5497
corresponding: true
email: steve@curvenote.com
roles:
- Investigation
- Project administration
- Software
- Visualization
- Curvenote
- name: Rowan Cockett
orcid: 0000-0002-7859-8394
corresponding: false
roles: []
affiliations:
- Curvenote
keywords:
- La Palma
- Earthquakes
abstract: | In September 2021, a significant jump in seismic activity on the island of La Palma (Canary Islands, Spain) signaled the start of a volcanic crisis that still continues at the time of writing. Earthquake data is continually collected and published by the Instituto Geográphico Nacional (IGN). ... plain-language-summary: | Earthquake data for the island of La Palma from the September 2021 eruption is found ... key-points:
- A web scraping script was developed to pull data from the Instituto Geogràphico Nacional into a machine-readable form for analysis
- Earthquake events on La Palma are consistent with the presence of both mantle and crustal reservoirs.
date: last-modified bibliography: references.bib citation: container-title: Earth and Space Science number-sections: true
Introduction¶
import matplotlib.pyplot as plt
import numpy as np
eruptions = [1492, 1585, 1646, 1677, 1712, 1949, 1971, 2021]
#| label: fig-timeline
#| fig-cap: Timeline of recent earthquakes on La Palma
#| fig-alt: An event plot of the years of the last 8 eruptions on La Palma.
plt.figure(figsize=(6, 1))
plt.eventplot(eruptions, lineoffsets=0, linelengths=0.1, color='black')
plt.gca().axes.get_yaxis().set_visible(False)
plt.ylabel('')
plt.show()
#| output: false
avg_years_between_eruptions = np.mean(np.diff(eruptions[:-1]))
avg_years_between_eruptions
79.83333333333333
Based on data up to and including 1971, eruptions on La Palma happen every 79.8 years on average.
Studies of the magma systems feeding the volcano, such as @marrero2019, have proposed that there are two main magma reservoirs feeding the Cumbre Vieja volcano; one in the mantle (30-40km depth) which charges and in turn feeds a shallower crustal reservoir (10-20km depth).
Eight eruptions have been recorded since the late 1400s (@fig-timeline).
Data and methods are discussed in @sec-data-methods.
Let $x$ denote the number of eruptions in a year. Then, $x$ can be modeled by a Poisson distribution
$$ p(x) = \frac{e^{-\lambda} \lambda^{x}}{x !} $${#eq-poisson}
where $\lambda$ is the rate of eruptions per year. Using @eq-poisson, the probability of an eruption in the next $t$ years can be calculated.
| Name | Year |
|---|---|
| Current | 2021 |
| Teneguía | 1971 |
| Nambroque | 1949 |
| El Charco | 1712 |
| Volcán San Antonio | 1677 |
| Volcán San Martin | 1646 |
| Tajuya near El Paso | 1585 |
| Montaña Quemada | 1492 |
: Recent historic eruptions on La Palma {#tbl-history}
@tbl-history summarises the eruptions recorded since the colonization of the islands by Europeans in the late 1400s.
{#fig-map}
La Palma is one of the west most islands in the Volcanic Archipelago of the Canary Islands (@fig-map).
{{< embed notebooks/data-screening.ipynb#fig-spatial-plot >}}
@fig-spatial-plot shows the location of recent Earthquakes on La Palma.