Decoded Science

  • Home
  • Headlines
  • General Science
  • Applied Science
    • Calculations
    • Economics
    • Engineering
      • Aviation
      • Civil Engineering
    • Medical Science
      • Health
      • Neuroscience
      • Oncology
      • Veterinary Science
    • Political Science
      • Polling
    • Mathematics
    • Technology
      • Artificial Intelligence
      • Computing
      • Electronics
      • Gadgets
    • Social Science
      • Cognitive Science
      • Psychology
      • Sociology
      • Anthropology
        • Linguistics
  • Physical Science
    • Archaeology
    • Astronomy
    • Chemistry
      • Materials Science
    • Geoscience
      • Climate Change
      • The Environment
      • Geology
      • Meteorology
      • Oceanography
    • Life Science
      • Biology
        • Botany
        • Zoology
          • Marine Biology
          • Entomology
          • Microbiology
        • Paleontology
        • Ecology
    • Nuclear Science
  • Theoretical Science
    • Physics
    • Math Theory
  • About Us
    • Contact Decoded Science
    • Ask the Expert
    • Meet Our Experts
    • Meet Our Sponsors:
    • Browse All Articles
    • Subscribe
    • Privacy Policy
    • Terms of Use Agreement
  • Support Decoded Science

Guam, Sweden and Texas: Earthquakes 11-17 September 2014

September 17, 2014 by Jennifer Young Leave a Comment

Share16
+1
Tweet
Share
Pin
16 Shares
Earthquakes 11-17 September 2014. Image credit: USGS

Earthquakes 11-17 September 2014. Image credit: USGS

The week of 11-17 September saw just one significant earthquake of at least magnitude 6 (≥M6.0) recorded on the United States Geological Survey’s real time earthquake map.

The map, which includes tremors of all magnitudes in the US and its territories and those of ≥M4.0 elsewhere, included a total of 1492 tremors of which 34 were ≥M5.0.

As usual, the distribution of larger tremors is closely associated with the margins of the planet’s tectonic plates.

Most notably, perhaps, the cluster of earthquakes associated with the subsidence of the crater at Iceland’s Bárðarbunga volcano continues, with eight tremors of ≥M4.5 recorded this week, the largest of them with a magnitude of 5.3.

A second cluster of earthquakes, this time five of them, occurred in Afghanistan along the western margin of the Himalayas.




M6.7, Guam: The Week’s Biggest Earthquake

Tectonic setting of the M6.7 Guam earthquake. Image credit: USGS

Tectonic setting of the M6.7 Guam earthquake. Image credit: USGS

Initially recorded at M7.1 but later downgraded to M6.7, the largest tremor of the week occurred on 17 September around 45 km west of the island of Guam.

Despite its offshore location and its magnitude (which approached that generally considered a threshold for generating a potentially destructive wave) no tsunami occurred.

This is likely to be because the tremor was just not quite large enough – and also because of its depth at 136km. Deeper tremors are less likely to be tsunamigenic because their energy is more easily dissipated.

Tectonically speaking the tremor looks likely to to be a classic subduction zone earthquake. The westward movement of the old, cold, dense crust of the Pacific plate leads to its subduction beneath the Philippine Sea plate, and such a setting leads to frequent, sometimes very large, tremors.

The island chain of Guam lies along this subduction zone – which, incidentally, includes the deepest known point on the Earth’s surface where the Marianas Trench reaches almost 11,000 metres.

From the limited available information at the time of writing, it appears likely that the Guam earthquake of 17 September was the result of movement at or near the plate interface.

M4.7 Quake in Central Sweden

Sweden's M4.7. Image credit: USGS

Sweden’s M4.7. Image credit: USGS

Small earthquakes can be fascinating. This week, one of noteworthy the features on the USGS map was a tremor of M4.7 in south-central Sweden, far from any tectonic plate margin.

Yeats draws attention to the existence of a series of recent (postglacial) faults which probably developed as a result of stresses in the crust following the last ice age.

Although these are largely to the north of this week’s tremor, it isn’t impossible that other faults resulting from the pressure of ice may exist further south and have gone unrecorded.

We may speculate, therefore, that the earthquake was the result either of movement along an old but possibly reactivated fault.

This quake may also have been caused by altering tectonic stresses following isostatic rebound (where the crust moves up once the weight of ice is removed).

US Earthquakes: Texas Gets in on the Act

Texas earthquakes 11-17 September. Image credit: USGS

Texas earthquakes 11-17 September. Image credit: USGS

So, Oklahoma….you can do earthquakes? Texas can do them too.

This week saw four small tremors across the state – two near Dallas, one near Charlotte and one near Snyder.

Although there’s no available evidence to link these directly to human activity, the USGS has linked the Oklahoma earthquake swarm to wastewater injection, and more recent work has suggested that this is also the cause of low-level seismic captivity in New Mexico and Colorado.

Bearing this in mind it seems possible that the Texas ‘quakes may have an anthropogenic source (although it’s also possible that they are natural).

Either way, Texas has a long way to go before it begins to match the scale of abnormal seismic activity being shown by its neighbour.

Varying Causes of Earthquakes

Larger earthquakes are generally the result of stresses at plane margins, as the Guam tremor shows. But intra-plate earthquake can also occur, either as result of other types of tectonic activity (as in Sweden) or as the result of human activity, which may be the case in Texas this week.

Share16
+1
Tweet
Share
Pin
16 Shares

Filed Under: Geoscience, Headlines Tagged With: recent earthquakes

Resources for this article

Physics. Wastewater injection is culprit for most quakes in southern Colorado and northern New Mexico. (2014). Accessed on September 17, 2014


United States Geological Survey. Real time earthquake map. (2014). Accessed on September 17, 2014


Yeats, Robert. Active Faults of the World. (2012). Cambridge University Press.




Decoded Everything is a non-profit corporation, dependent on donations from readers like you. Donate now! Your support keeps the great information coming!

Donation Information

I would like to make a donation in the amount of:

$500$200$100$50$20$10$5Other
Other:

I would like this donation to automatically repeat each month

Tribute Gift

Check here to donate in honor or memory of someone
Check here if this is a memorial gift
Name of person to be honored:
Send acknowledgement via email
Send acknowledgement via postal mail
Email Name:
Email:
Name:
Address:
City:
State :
Province:
Country:
Postal Code:

Donor Information

First Name:
Last Name:
Email:
Please do not display my name publicly. I would like to remain anonymous
Add me to your mailing list

Leave a Reply Cancel reply

Connect with:
Facebook

Your email address will not be published. Required fields are marked *

About the Author

Jennifer Young

Jennifer Young gained an Honours degree in Geography from Edinburgh University, where her studies included a range of topics in both physical and environmental geography. She subsequently undertook and completed a BSc in ... Read Full Profile

Follow Decoded Science

  • Facebook
  • Google+
  • Twitter
  • Pinterest
signupheredailydosedecsciv2


Science Everyone's Talking About

  • Effects of Poor Sleep: Increased Bickering with Your Partner Effects of Poor Sleep: Increased Bickering with Your Partner New research shows that not only can poor sleep habits... under Headlines, Social Science
  • Himalayan Ice Loss, Extra-Terrestrial Water and the European Settlement of the Americas: Geoscience 1-7 February 2019 Himalayan Ice Loss, Extra-Terrestrial Water and the European Settlement of the Americas: Geoscience 1-7 February 2019 This week we go back in time, travel into outer space a... under Geoscience, Headlines, Weekly Features
  • Air Conditioning and Pressurization Systems in Modern Aircraft Air Conditioning and Pressurization Systems in Modern Aircraft For any modern aircraft to fly at high altitudes, i... under Aviation
  • Martian Water, Vanishing Arctic Ice and Mediterranean Tsunami Risk: Geoscience 6-13 February 2019 Martian Water, Vanishing Arctic Ice and Mediterranean Tsunami Risk: Geoscience 6-13 February 2019 This week's articles include the case for liquid water... under Geoscience, Headlines, Weekly Features
  • Introducing the Factorial: the Exclamation Mark of Math Introducing the Factorial: the Exclamation Mark of Math What is a factorial, and how is the exclamation point u... under Math Theory

Today's Most Popular Science Articles

  • Introducing Math Symbols for Union and Intersection Introducing Math Symbols for Union and Intersection
  • Genetically Modified Organisms: Pros and Cons of GMO Food Genetically Modified Organisms: Pros and Cons of GMO Food
  • Which Chemical Bond is Stronger: Ionic vs. Covalent Bonds Which Chemical Bond is Stronger: Ionic vs. Covalent Bonds
  • Norovirus Facts: 5 Things You Didn't Know About Stomach Flu Norovirus Facts: 5 Things You Didn’t Know About Stomach Flu
  • Introducing the Factorial: the Exclamation Mark of Math Introducing the Factorial: the Exclamation Mark of Math
  • Cross Multiply to Solve Equations with Fractions Cross Multiply to Solve Equations with Fractions
  • Stomach Flu Cramps: Is There Anything You Can Do For Norovirus Symptoms? Stomach Flu Cramps: Is There Anything You Can Do For Norovirus Symptoms?

Copyright © 2019 · Magazine Pro Theme on Genesis Framework · WordPress · Log in

MENU
  • Home
  • Headlines
  • General Science
  • Applied Science
    • Calculations
    • Economics
    • Engineering
      • Aviation
      • Civil Engineering
    • Medical Science
      • Health
      • Neuroscience
      • Oncology
      • Veterinary Science
    • Political Science
      • Polling
    • Mathematics
    • Technology
      • Artificial Intelligence
      • Computing
      • Electronics
      • Gadgets
    • Social Science
      • Cognitive Science
      • Psychology
      • Sociology
      • Anthropology
        • Linguistics
  • Physical Science
    • Archaeology
    • Astronomy
    • Chemistry
      • Materials Science
    • Geoscience
      • Climate Change
      • The Environment
      • Geology
      • Meteorology
      • Oceanography
    • Life Science
      • Biology
        • Botany
        • Zoology
          • Marine Biology
          • Entomology
          • Microbiology
        • Paleontology
        • Ecology
    • Nuclear Science
  • Theoretical Science
    • Physics
    • Math Theory
  • About Us
    • Contact Decoded Science
    • Ask the Expert
    • Meet Our Experts
    • Meet Our Sponsors:
    • Browse All Articles
    • Subscribe
    • Privacy Policy
    • Terms of Use Agreement
  • Support Decoded Science