Educational and citizen seismology

What would happen if time could run backwards as well as forwards ?  Well seismologists can run time backwards in a computer and work out where an earthquake has happened.  We know what time a seismic wave reaches a monitoring station, and we know the speed it travels.  If we run time backwards we can then work out the locus of possible origins for the source of the earthquake at each time in the past, for each station this will be a circle of possible origin locations that increases in size as we go back in time.   With three or more stations the origin location (and time) of the event can be estimated from the point when all of these possible locations converge on one point. A simple python program and some data from a recent earthquake in Cornwall illustrates this principle import matplotlib.pyplot as plt import math import numpy as np from matplotlib.patches import Circle import matplotlib.animation as animation from matplotl...

How big was it ?   That's what everyone wants to know about earthquakes.   Seismologists calculate earthquake magnitudes by measuring the amplitude of the wiggles recorded on seismometers and applying a correction factor to account for how far away the earthquake was.    The first person to do this was Charles Richter, he called the results of his calculations the Richter Magnitude. In the UK seismologists use a formula that calculates the 'Local earthquake magnitude' (see https://academic.oup.com/gji/article/216/2/1145/5185119 )        amp is seismogram displacement in nm (0.5x peak-peak) and  distance r is in  km  ML=log(amp) + 1.11log(r) +0.00189r -1.16e^-0.2r -2.09 For the 8 August 2019 cornwall earthquake we can calculate the magnitude for each seismogram station CCA1 magnitude Ml= 2.3 station RB30C magnitude Ml= 2.7 station RB5E8 magnitude Ml= 2.2 station RD93E magnitude Ml= 2.4 station R82BD magnitude ...

So an earthquake has happened... you have see some seismograms using the excellent Python Obsy toolkit and some simple scripts... now you want to plot a map or two. Simple location map created in Python using the Folium library   import folium # setting the boundaries of the map and choosing a map style m = folium . Map ( location = [ 50.067 , - 5.187 ], zoom_start = 10 , tiles = 'Stamen Terrain' ) # put a marker on the map for the reported BGS earthquake location folium . Marker ( location = [ 50.067 , - 5.187 ], popup = 'quake' , icon = folium . Icon ( color = 'red' )) . add_to ( m ) # next add markers for the locations of all the seismic monitoring stations in Cornwall folium . Marker ( location = [ 50.1867 , - 5.2273 ], popup = 'BGS_CCA1' , icon = folium . Icon ( color = 'green' )) . add_to ( m ) folium . Marker ( location = [ 50.1486 , - 5.0945 ], popup = 'FL_RB30C' , icon = folium . Icon ( color = 'green...

On 8th August 2019 a small earthquake happened in Cornwall, UK.   Despite being less than magnitude 3 it caused great excitement locally, and even nationally. At the time this earthquake happened the deep geothermal energy company United Downs had just set up a network of low cost raspberryshake seismometers in local schools as part of their community outreach programme.    Deep geothermal well being drilled in Cornwall  Raspberryshake citizen seismology stations in Europe  These simple, lowcost seismometers easily detected the signal from this earthquake right across the county.    Data from these sensors can be downloaded from an online archive using simple Python programs and using the ObsPy Python library from obspy.clients.fdsn import Client from obspy import UTCDateTime import matplotlib.pyplot as plt # station names seislist = [ 'RB30C' , 'RB5E8' , 'RD93E' , 'R82BD' , 'R7FA5' ] # set the data window start...

Plots most recent data from CWF

It has long been known that large crowds can generate seismic signals if they all move together, this can be dancing to a common  beat ( eg the Ska band Madness at the Reading Festival )  or crowds at sporting fixtures responding to events on the pitch ( eg the Seattle Seahawks and their BeastQuakes ) In Leicester during the 2015-2016 football season Leicester were performing beyond all expectations, the city was buzzing with excitement as Leicester reached the halfway point of the season as top of eth English premier League.   At this point students from Leicester University (wth help from the British Geological Survey) started an outreach project at a city centre primary school, Hazel Road, about 500m from the Leicester football ground, the King Power stadium. Over the course of the next few months Leicester went on to win the Premiership and the students from Leicester University and Hazel road primary school were there all along the way monitoring the seismic v...