Earthquake!

By Jane Cruickshank / September 25, 2019
Seismic chart print out

SCIENTISTS from the British Geological Survey recorded an earthquake in the Central North Sea yesterday, measuring 4.2 on the Richter Local Magnitude scale – and detected at a seismic station close to Stonehaven.

Earthquake seismologist David Galloway told The Bellman the quake was located in the Elgin-Franklin Oil Field region.

He said: ”We have received a report from the Elgin-Franklin Offshore Field that this event was felt, by several people, on the PUQ offshore oil platform.  The reports described  ‘a moderate shaking feeling’.”

Mr Galloway provided the following information:

SEISMIC INFORMATION : CENTRAL NORTH SEA  24 SEPTEMBER 2019  13:38 UTC  4.2 ML

DATE                    :       24 September 2019
ORIGIN TIME             :       13:38 15s UTC
LAT/LONG                :       57.030° North / 1.949° East
GRID REF                :       639.6 kmE / 800.1 kmN
DEPTH                   :       10 Km
MAGNITUDE               :       4.2 ML
LOCALITY                :       Central North Sea, approximately 240 km east of Aberdeen
INTENSITY                :       3 EMS

You learn something every day

UTC is Coordinated Universal Time, which is the successor to Greenwich Meantime and also called ‘Zulu’ in the military.

The magnitude of an earthquake is a measure of the strength of an earthquake. There are several scales depending on which part of the seismogram is examined. These include Richter local magnitude (ML), Body wave magnitude (mb) and surface wave magnitude (Ms). Moment magnitude (Mw) is calculated from spectral analysis.

And the intensity is a measure of the effects of an earthquake at a particular place on humans and (or) structures. The intensity at a point depends not only upon the strength of the earthquake (magnitude) but also upon the distance from the earthquake to the epicentre and the local geology at that point.

According to a synopsis of the European Macroseismic Scale (EMS 98), 3EMS is classified as weak – the vibration is weak and is felt indoors by a few people. People at rest feel a swaying or light trembling.

Mr Galloway also provided the following seismogram of the event as recorded on 6 of the British Geological Survey’s seismic stations … PGB (Glennifer Braes, Strathclyde), MCD (Elgin), GDLE (Glaisdale, North Yorkshire), ESK (Eskdalemuir), EDMD (Edmundbyers, Co Durham) & DRUM (Mains of Drumtochty, Aberdeenshire)

A wealth of information about earthquakes and the British Geological Survey – including the following video – is available on their website

A wee humourous note – when working at the Mearns Leader during a slow, slow news week, I once put together a 350 word page lead story about a rainbow. Earthquake! makes for a much better headline.

About the author

Jane Cruickshank

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