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

M6.9 California Earthquake: Largest Tremor for Seven Years Strikes off Cape Mendocino

March 10, 2014 by Jennifer Young Leave a Comment

Share40
+1
Tweet
Share
Pin
40 Shares
Location and tectonic setting of the earthquake of 10 March 2014. Image credit: USGS

Location and tectonic setting of the earthquake of 10 March 2014. Image credit: USGS

An earthquake of magnitude 6.9 (M6.9) which struck off the coast of north California on 10 March is the largest to hit the region since an M7.2 which occurred in the same area seven years ago.

Early reports recorded by the United States Geological Survey suggest that residents felt the quake as far south as San Francisco but at the time of writing there’s no indication of any damage.

M6.9 Ferndale Earthquake: Location and Tectonic Setting

The west coast of North America marks a continental margin. In both north and south, the North American plate marches alongside the Pacific plate and the plate margin is conservative, with the plates sliding past one another.

Between California’s Cape Mendocino and a point to the north of Vancouver Island, however, the remnant of an ancient plate (the Juan de Fuca plate) is moving against the North American continent and being forced beneath it – an area known to seismologists as the Cascadia subduction zone.

The earthquake occurred to the south of this zone, close to the Mendocino triple junction – a point where the plate boundaries between the North American and Pacific plates, the Juan de Fuca and Pacific plates (both conservative boundaries) and the the North American and Juan de Fuca plate (subduction zone) meet.

With conflicting stresses resulting from different directions of movement, there are high levels of deformation and fault maps show fold and thrust belts parallel to the coast both on and off shore.

Data published by the USGS at this early stage are limited, but the shallow depth of the earthquake (around 16.6km) suggests that it was this internal deformation that caused the tremor, rather than the collision between the two continents.

This is supported by the absence of any tsunami, indicating that there was little or no vertical displacement.

Historic Earthquakes in Cascadia and the Mendocino Fault Zone

Historic earthquakes of M6.0 or greater since 1900 around the Mendocino triple junction. Image credit: USGS

Historic earthquakes of M6.0 or greater since 1900 around the Mendocino triple junction. Image credit: USGS

This suggestion of the probable cause of the tremor is supported by a look at the distribution of large earthquakes in the region. A map drawn from the USGS database of historic earthquake shows that large tremors (≥M6.0) in the region since 1900 cluster around the triple junction and the southern and eastern margins of the Juan de Fuca plate.

The leading edge of the plate (the subducting part) shows a clear absence of large tremors, indicating that the subduction zone is presently inactive, other because it is aseismic or because it is ‘locked’ (in other words, strain continues to build).

The map shows clearly how significant today’s tremor was in terms of size; it is the eighth largest recorded in the area since 1900. The largest, at M7.3, occurred in 1980 and on average the region has experienced a tremor of M6.0 or greater around every three years.

Earthquakes, Fault Margins, and Tremor Damage

Earthquakes at this type of margin and of this nature are typically not damaging. They lack a vertical component to the movement, so tremors of this nature are unlikely to generate tsunamis – and they are also located at distance from major population centres. Other tremors can have much greater impact, however: In 1989, an earthquake of the same magnitude struck the San Andreas Fault Zone. That tremor, at Loma Prieta in California, killed 63 people and caused extensive damage.

Share40
+1
Tweet
Share
Pin
40 Shares

Filed Under: Geology, Headlines Tagged With: california earthquake

Resources for this article

United States Geological Survey. Real time earthquake map. (2014). Accessed on March 10, 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

  • Genetically Modified Organisms: Pros and Cons of GMO Food Genetically Modified Organisms: Pros and Cons of GMO Food What are the benefits and risks of genetically modified... under Headlines, Health
  • Birthdays Can Have Power, Perfection, And Abundance: Fun With Numbers Birthdays Can Have Power, Perfection, And Abundance: Fun With Numbers The numbers associated with the years in a human life s... under Headlines, Mathematics
  • Chemistry Questions: Organic Compounds, Life, and Vitalism Chemistry Questions: Organic Compounds, Life, and Vitalism Current scientific theories as to the origin of life ar... under Chemistry
  • Comparing the Genetic Code of DNA to Binary Code Comparing the Genetic Code of DNA to Binary Code Does DNA store information in the same way that a compu... under Information Science, Mathematics
  • 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

Today's Most Popular Science Articles

  • Norovirus Facts: 5 Things You Didn't Know About Stomach Flu Norovirus Facts: 5 Things You Didn’t Know About Stomach Flu
  • Introducing Math Symbols for Union and Intersection Introducing Math Symbols for Union and Intersection
  • Which Chemical Bond is Stronger: Ionic vs. Covalent Bonds Which Chemical Bond is Stronger: Ionic vs. Covalent Bonds
  • Genetically Modified Organisms: Pros and Cons of GMO Food Genetically Modified Organisms: Pros and Cons of GMO Food
  • 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