Recent Earthquake Teachable Moments

February 4, 2010 (20:20:21 UTC)

Quake Location

Magnitude 5.9 Offshore Northern California

This earthquake occurred north of the Mendocino Transform Fault, inside the Gorda plate, which is deforming as the Gorda Plate and Pacific plate slide past each other. The fault motion during the earthquake was strike-slip (side-by-side like the San Andreas Fault) with the Gorda Plate moving east and while the Pacific plate jumped west along the Mendocino Transform Fault.

Teachable Moment Presentation

En Español


January 12, 2010 (21:53:10 UTC)

Quake Location

Magnitude 7.0 Haiti

A major earthquake occurred Tuesday in the boundary region separating the Caribbean plate and the North America plate. This plate boundary is dominated by left-lateral strike slip motion and compression, and accommodates about 20 mm/y slip, with the Caribbean plate moving eastward with respect to the North America plate.

Teachable Moment Presentations

Animations and Visualizations

  • Seismic Wave Propagation (Youtube / Quicktime)
  • Why didn't the magnitude 7 earthquake in Haiti cause a large tsunami? (Youtube / Quicktime)
  • USArray Wave Visualization Globe (Youtube / Quicktime 15MB)
    -watch seismic waves from the Haiti earthquake as they cross the USArray's seismometer deployment. Blue circles indicate a seismometer moving down; red circles indicate a seismometer moving up.
    Click here to learn more.
  • Six Month Seismic Monitor Central America Earthquake Activity Map (Youtube / Quicktime 6.7MB)
  • updated 20 Jan Seismic Monitor View of the Haiti earthquake and aftershocks (Flash) or with color coded magnitude (Quicktime).

To save the videos above, right click a Quicktime link and choose "Save Target As".

USGS Resources

En Español

Additional Haiti Earthquake Resources


January 9, 2010 (00:27:39 UTC)

Quake Location

Magnitude 6.5 Offshore Northern California

This earthquake occurred approximately 35 km WNW of Ferndale, CA in a deformation zone of the southernmost Juan de Fuca plate that is commonly referred to as the Gorda plate. The earthquake's epicenter is northwest of the Mendocino Triple Junction, which is formed by the intersection of the Mendocino fracture zone, the San Andreas fault and the Cascadia subduction zone. (USGS National Earthquake Information Center)

Presentation

University of Portland/IRIS Earthquake Notice (pdf)
12 slide Teachable Moment Powerpoint (zipped)
Converted powerpoint (pdf)

En Español

Presentación en Español (ppt 3MB)


January 3, 2010 (22:36:28 UTC)

Quake Location

Magnitude 7.1 Solomon Islands

The Solomon Islands earthquake of January 3, 2010, likely occurred at the boundary between the Pacific and Australian plates, where the Australian plate subducts beneath the Pacific towards the northeast at a rate of approximately 95 mm/yr. (USGS National Earthquake Information Center)

Presentation

University of Portland/IRIS Earthquake Notice (pdf)

Individual Files

Seismic wave propagation (Quicktime Animation)

En Español

Propagación de Ondas Sísmicas (Animación Quicktime)

Additional Resources

Maps
USGS Earthquake Hazards Program


December 30, 2009 (18:48:57 UTC)

Quake Location

Magnitude 5.9 Baja California, Mexico

The northern Baja California earthquake of December 30, 2009, occurred on the principal plate boundary between the North America and Pacific plate. At the latitude of the earthquake, the Pacific plate moves northwest with respect to the North America plate at 45 mm/y. (USGS National Earthquake Information Center)

Presentation

9 slide powerpoint (zipped, includes animation)
University of Portland/IRIS Earthquake Notice (pdf)
Converted powerpoint (pdf)

Individual Files

Seismic wave propagation (Quicktime Animation)

En Español

Presentación en Español (Archivo Zip)
Propagación de Ondas Sísmicas (Animación Quicktime)

Additional Resources

USGS CoreCast


November 17, 2009 (15:30:46 UTC)

Quake Location

Magnitude 6.6 Queen Charlotte Islands Region

A strong earthquake occurred on the Queen Charlotte transform fault.  The Pacific Plate moves north-northwest approximately parallel to the Queen Charlotte transform fault that connects the Explorer Ridge (an extension of the Juan de Fuca Ridge) with the Aleutian Trench.

Presentation

University of Portland/IRIS PDF Earthquake Notice
Seismic wave propagation (Quicktime Animation)


November 9, 2009 (10:44:54 UTC)

Quake Location

Magnitude 7.3 Fiji

The Fiji earthquake of 9 November 2009 occurred at the northern end of the inclined seismic zone that dips to the west beneath Tonga and Fiji. The broad-scale tectonics of the earthquake region are dominated by the relative convergence of the Pacific and Australia plates. At the latitude of the earthquake, the Pacific plate moves westward with respect to the interior of the Australia plate at a velocity of about 86 mm/yr. (USGS National Earthquake Information Center)

Presentation

University of Portland/IRIS PDF Earthquake Notice
Seismic wave propagation (Quicktime Animation)


Novermber 4, 2009 (12:38:29 UTC)

Quake Location

Magnitude 5.3 Off the Coast of Oregon

This moderate earthquake occurred on the Blanco Fracture Zone that is a transform boundary between the Juan de Fuca and Pacific plates.  The direction of relative motion between these plates along the Blanco Fracture Zone is right-lateral horizontal strike-slip.  Although earthquakes occur frequently along the Blanco Fracture Zone, they are rarely felt in Oregon or Washington because they are moderate magnitude and a significant distance from the coast.

Presentation

University of Portland/IRIS PDF Earthquake Notice


October 7, 2009 (22:03:15 UTC)

Quake Location

Magnitude 7.7 Vanuatu

The Torres Islands, Vanuatu earthquake of October 7, 2009, occurred on or near the plate boundary between the Australia and Pacific plates. In the region of the earthquake, the Australia plate moves to the east-northeast with respect to the Pacific plate at a velocity of about 91 mm/year.  (USGS National Earthquake Information Center)

Presentation

Powerpoint  (zipped files, includes both animations)
Presentación en Español (ppt)
Presentation (PDF)

Individual Files

Seismic wave propagation (Quicktime Animation)
Propagación de Ondas Sísmicas (Animación Quicktime)

Additional Resources

University of Portland/IRIS PDF Earthquake Notice

 


September 30, 2009 (10:16:09 UTC)

Quake Location

Magnitude 7.6 Southern Sumatra, Indonesia

As the Australia – Indian Plate subducts below the Eurasian Plate at a velocity of about 60 mm/yr (6 cm/yr), earthquake depths increase from southwest to northeast across this plate boundary. The earthquake of September 30, 2009 nicely fits the pattern of depths for earthquakes that occur on the subsurface interface between the Australia – Indian and Eurasian plates. This earthquake did not produce a tsunami because it occurred at a depth of 81 km, far below the seafloor.

Presentation

University of Portland/IRIS PDF Earthquake Notice


September 29, 2009 (17:48:10 UTC)

Quake Location

Magnitude 8.1 Samoa Islands Region

This great earthquake occurred near the northern end of the Tonga Trench where the Pacific Plate subducts below the India-Australia Plate.  This earthquake occurred about 200km south of the island of Upolu.  The rate of convergence at the Tonga Trench is about 80mm/yr (8cm/yr) and this is one of the most seismically active subduction zones on Earth.

Presentation

Zipped Files  (includes animation)
Presentación en Español (Archivo Zip)
Presentation (PDF)

Individual Files

Seismic wave propagation (Quicktime Animation)
Propagación de Ondas Sísmicas (Animación Quicktime)

Additional Resources

University of Portland/IRIS PDF Earthquake Notice
NOAA Tsunami realtime movie

 


September 12, 2009 (20:06:24 UTC)

Quake Location

Magnitude 6.3 Offshore Venezuela

The September 12, 2009 earthquake offshore of Venezuela occurred at a shallow depth as a result of right-lateral strike-slip faulting. The tectonics of this area are dominated by the eastward motion of the Caribbean plate with respect to the South American plate, at a rate of approximately 20mm/yr. (USGS National Earthquake Information Center)

Presentation

Zipped Files  (includes animation)
Presentación en Español (ppt)
Presentation (PDF)

Individual Files

Seismic wave propagation (Quicktime Animation)
Strike Slip Animation (Quicktime Animation)
Propagación de Ondas Sísmicas (Animación Quicktime)

 


May 28, 2009 (08:24:45 UTC)

Quake Location

Magnitude 7.3 Offshore Honduras

The location and focal mechanism of the Honduras earthquake of May 28, 2009, imply that the shock occurred as the result of left-lateral strike-slip faulting on the Swan Islands Transform Fault, a segment of the boundary between the North America and Caribbean plates. In this region the plate boundary accommodates about 20 mm/y slip.  (USGS National Earthquake Information Center)

Zipped Files  (includes animation)
Presentación en Español (ppt)
Presentation (PDF)

Individual Files

Seismic wave propagation (Quicktime Animation)
Propagación de Ondas Sísmicas (Animación Quicktime)

Additional Resources

University of Portland/IRIS PDF Earthquake Notice


April 6, 2009 (01:32:42 UTC)

Quake Location

Magnitude 6.3 Central Italy

The April 6th 2009 earthquake in Central Italy occurred as a result of normal faulting on a NW-SE oriented structure in the central Apennines, a mountain belt that runs from the Gulf of Taranto in the south to the southern edge of the Po basin in northern Italy. Geologically, the Apennines are largely an accretionary wedge formed as a consequence of subduction. (USGS National Earthquake Information Center)

 

Presentation

Powerpoint  
Presentación en Español (ppt)
Presentation (PDF)