Geology News - Earth Science Current Events

The US Geological Survey has a website where you can create earthquake probability maps for the area surrounding a specific location that you specify. You can also specify the recurrence interval and earthquake magnitude. Shown below is a map that illustrates the probability of an earthquake of 6.01 magnitude or higher occurring during the next 100 years for the area surrounding Wellsboro, Pennsylvania.


Earthquake probability map produced at the USGS website.
Your map can be output in .gif, .pdf, or .ps format and you can get an ASCII file of the raw data.

Create an earthquake probability map at the USGS website.

Labels: Earthquakes

---

New Madrid and Wabash Valley Seismic Zones - Image by USGS

USGS has a new geologic hazards fact sheet titled "Earthquake Hazard in the Heart of the Homeland". This publication gives an overview of earthquake activity in the New Madrid and Wabash Valley seismic zones. These have produced historic earthquake activity that has strongly shaken portions of Missouri, Kentucky, Tennessee, Arkansas, Illinois and Indiana with effects reaching beyond those states. Three of the largest earthquakes in the continental United States occurred in the New Madrid seismic zone in 1811 and 1812.

Studies of historic seismic activities in these areas suggest that within the next 50 years an earthquake of 7.5 to 8.0 magnitude has a 7 to 10 percent chance of occurring and an earthquake of 6.0 magnitude or greater has a 25 to 40 percent chance of occurring.

Read the Earthquake Hazard in the Heart of the Homeland factsheet at the USGS website. They also have an older .pdf poster titled Earthquakes in the Central United States - 1699 to 2002 which contains a good summary about this issue with interesting historical perspectives on earthquakes that occurred in this area during 1843, 1895, 1968, 1987 and 2002.

Labels: Earthquakes

---

Image by USGS

The major earthquake that occurred off the coast of Taiwan on December 26 fortunately did not cause an extreme amount of damage on the island. USGS reports that the 7.1 magnitude earthquake and its many aftershocks (one a 6.9) killed at least one person, injured at least three, and destroyed or damaged several buildings in the P'ing-tung area.

A big casualty from this earthquake was the undersea fiber-optic cables that carry voice and data communications both to and from the island. Even though wireless forms of communication are possible a majority of transmissions still flow through cables. The cables are normally extremely reliable but this event demonstrates a vulnerability.

Phone companies, banks, news agencies, currency traders, credit card processors, brokerages and millions of internet users were abruptly cut off when the cable was damaged. Repairs are expected to take a few weeks. Fortunately some of the traffic was able to be rerouted after several hours of outage, however, access is very slow because of congestion.

The only way to prevent this type of disruption is to have multiple cables taking separate routes which do not cross the same hazardous area. This is especially important for island nations such as Taiwan and Japan who depend upon cables to deliver electronic communications and are located where undersea cables must cross the earthquake-prone areas of active plate boundaries.

A good report on this situation is an article titled Taiwan quake shakes confidence in undersea links at Yahoo News.

Labels: Earthquakes

---

Yellowstone National Park is located above one of the largest active volcanic systems in the world. USGS has monitored the area for many years and has published a monitoring plan for 2006-2015 which includes new instrumentation to monitor new locations, collect new types of data and upgrade the current monitoring effort.


Proposed new stream monitoring, gas sampling, GPS, tilt, seismic and strain monitoring instruments to be added to the Yellowstone volcano and earthquake monitoring network. Thick black line is the boundary of the Yellowstone Caldera. Thin black lines are roads. Gray outline is park boundary. Red regions are thermal areas. Image by USGS
Yellowstone earthquake monitoring will be upgraded to modern standards and five new seismograph stations will be added to increase the observation density. Five borehole strainmeters and two tiltmeters will be installed to measure crustal movements. New stream gages, and gas-measuring instruments will enable scientists to compare geophysical phenomena, such as earthquakes and ground motions, to hydrothermal events, such as anomalous water and gas discharge. In addition, USGS hopes to characterize the behavior of geyser basins to detect any precursors to hydrothermal explosions and to monitor earthquakes related to fluid movements. Finally, a secure system for real-time transmission of data will ensure that important data is not lost at critical times.

Read the entire 17-page report: Volcano and Earthquake Monitoring Plan for the Yellowstone Volcano Observatory, 2006-2015

Related Article on Geology.com - Uplift at Yellowstone Caldera

Labels: Earthquakes, Geothermal, Volcanoes

---

Image by USGS

One of the most dangerous earthquake areas on earth is the Island of Honshu, Japan. Here the Pacific, North American, Eurasian and Philippine Plates converge to generate major earthquakes with an average recurrence interval of about 100 to 150 years. These major earthquakes are known as the "Tokai Earthquakes". The four most recent Tokai Earthquakes occurred in 1854, 1707, 1605 and 1498. All of these are estimated to have been 8+ magnitude earthquakes. A repeat of one of these events will cause thousands of deaths and hundreds of billions of dollars in damages.

The Japanese government is taking the Tokai Earthquakes seriously and has charged the Japan Meteorological Agency with the job of predicting the next one. They have a dense array of instruments placed to accumulate a continuous stream of data related to seismicity, strain, crustal expansion, tilt, tidal variations, ground water fluctuations and other variables. They are watching for an anomaly in this data which might precede the next major Tokai Earthquake.


Image by USGS

Read more about the Tokai Earthquakes at the Japan Meteorological Agency website.

Labels: Earthquakes

---

Image by USGS

A great earthquake of 8.3 Magnitude was reported by USGS, occurring in the Kuril Islands at 10:14 PM local time on Wednesday, November 15, 2006. The earthquake occurred at a depth of about 40km/25miles and numerous magnitude 6+ aftershocks are being recorded. There are no current reports of damage or injuries for this earthquake.

Tsunami watches and warnings were issued across the Pacific basin, however they have since been canceled for Alaska, west coast USA and Canada, Hawaii and other locations. A small tsunami was observed at the following sites...

• Hanasaki, Japan 30cm/1.0ft
• Hushiro, Japan 25cm/0.8ft
• Shemya, Alaska 20cm/0.65ft
• Amchitka, Alaska 8cm/0.25ft

Image by CIA

The Kuril Islands stretch from the island of Hokkaido, Japan to the Kamchatka peninsula of Russia and separate the Sea of Okhotsk from the Pacific Ocean. There are 56 islands spanning the 1300 km/700 mile chain.

Read more about this earthquake at the USGS Earthquake Information Center.

Labels: Earthquakes

---

Field Guide to the San Andreas Fault Cover. Copyright, David Lynch

David Lynch of Thule Scientific has published "Field Guide to the San Andreas Fault", a 200+ page driving tour guide for visiting the fault. This is one of the highest quality publications on the San Andreas Fault that I have seen.

It includes over 200 illustrations, some of which are exceptional in their educational value. The book is written to accommodate the beginner and expert. For the beginner there is background information about geologic structures and plate tectonics and an introduction to the San Andreas. The expert will benefit from the detailed field guide that can be used to visit numerous interesting locations along the fault.

Below is one of Dr. Lynch's illustrations. It shows the contact between the Pacific Plate and the North American Plate in outcrop.

San Andreas Fault near Gorman, California. The grey, metamorphic quartz monzonite on the left side of the fault
are rocks of the Pacific Plate and the brown sandstone and siltstone on the right of the fault are rocks of the
North American Plate. Photograph copyright by David Lynch.

The most important part of Dr. Lynch's book is the mile-by-mile annotated road log which contains hundreds of GPS coordinates. These maps and descriptions will guide you on twelve one-day field trips to easily accessed and educational locations along the fault. The trips are:

1. Salton Trough: Brawley to Desert Hot Springs
2. San Gorgonio Pass: Desert Hot Springs to San Bernardino
3. San Gabriel Mountains: San Bernardino to Palmdale
4. Leona Valley: Palmdale to Frazier Park
5. San Emigdio Mountains: Frazier Park to Soda Lake Road
6. Carrizo Plain: Soda Lake Road to Simmler
7. Palo Prieto Pass: Simmler to Parkfield
8. Franciscan Melange: Parkfield to Hollister
9. Heart of the Fault: Holister to Daly City
10. Marin Headlands and Point Reyes: Daly City to Point Reyes National Seashore
11. Bodega Head: Point Reyes National Seashore to Manchester State Beach
12. North Coast: Manchester State Beach to Point Delgada

Learn more about this San Andreas Fault Field Guide at ThuleScientific.com.

Related Article on Geology.com - The San Andreas Fault

Labels: Books-Publications, Earthquakes

---

Image by USGS

A strong 6.7 magnitude earthquake occurred on the northwest side of the Island of Hawaii at 7:07 AM local time. The earthquake caused landslides, power outages, disruption of telephone communications, and minor to moderate building damage on the northwest side of Hawaii. Some injuries have been reported but no deaths. The Pacific Tsunami Warning Center has not observed a tsunami associated with this earthquake.


Image by USGS
The map above shows intensity by zip code area based upon over 2000 citizen observations that have been reported to USGS. The earthquake was felt throughout the Hawaiian Islands with up to a VII intensity in the area surrounding the epicenter.

Earthquakes are a relatively common occurrence beneath the Island of Hawaii. Most are related to volcanic activity. This earthquake is on the opposite side of the island from where the current volcanic activity occurs.

Get more information at the National Earthquake Information Center

Labels: Earthquakes

---

Image by USGS

The United States Geological Survey detected Monday's nuclear test by North Korea. The seismic waves from the blast were interpreted as a light earthquake of 4.2 magnitude with a very shallow depth.

Location:
41.294°N, 129.134°E
Distances:

• 70 km (40 miles) N of Kimchaek, North Korea
• 90 km (55 miles) SW of Chongjin, North Korea
• 180 km (115 miles) S of Yanji, Jilin, China
• 385 km (240 miles) NE of Pyongyang, North Korea

See the USGS record of the North Korea Nuclear Test at the NEIC website.

Labels: Earthquakes

---

Image by USGS

It takes a long time to recover from an earthquake. After a strong 7.2 earthquake struck the port city of Kobe, Japan in 1995 recovery was a very slow process. It took nearly five years to rebuild the 140,000 homes that were destroyed. That is slow progress in a nation with a very strong economy, infrastructure and easy terrain.

Recovering from a devastating earthquake is a long, expensive and difficult process that requires years to complete.

Pakistani students in a restored school. Image by USAid.gov

In Pakistan, one year after the 7.6 earthquake killed over 70,000 people, destroyed or damaged about 650,000 housing units, and destroyed or damaged about 8,000 schools, the work is far from completed. Lack of funding, materials, transportation, communications, health care, technical support and even necessities are all barriers to progress. Thousands of people still are without homes and face a second winter of living in an unwinterized tent.

A detailed article on the status of the Pakistan earthquake recovery can be seen at Reuters AlertNet.

Labels: Earthquakes

---

Here is an interesting website by USGS that gives you near-real-time access to about 100 seismograms. The map below is from the website. The blue stars are recent earthquakes.


Image by USGS

The red dots are seismograph stations and (when you are on their site) clicking on the red dots will show you a near-real-time seismogram (updated every thirty minutes).

The #4 star is for an earthquake that occurred at 10:13:18 GMT on September 15th, 2006. This was a 5.7 M event in the New Britain Region of Papua New Guinea. If we click the red dot for the Port Moresby, New Guinea station - labeled PMG and partially hidden by the blue star the seismogram below is displayed. The earthquake is obvious on this seismogram.


Image by USGS

We can then trace the progress of seismic waves across Australia by clicking stations
CTAO (Charters Towers, Australia), MBWA (Marble Bar, Western Australia, and NWAO (Narrogin, Australia) respectively, as shown in the seismograms below.


Image by USGS


Image by USGS


Image by USGS

This type of data is not only interesting but can be of great value to teachers and students of geology. It could be used in a wide variety of assignments related to recent earthquakes, seismic wave propagation, and seismograph interpretation.

Check out the map and seismograms at the ASL DCC Telemetry Stations website.

Labels: Earthquakes

---

Image by USGS

Lots of people are going to the USGS "Did You Feel It?" page to report what they experienced as a result of Sunday morning's earthquake beneath the Gulf of Mexico. As of 9:30 PM, Sunday evening - a little over 12 hours after the earthquake - nearly 5000 people had provided data. You can see a plot of reports vs. time below.


Image by USGS

USGS is using this data to automatically compile an earthquake intensity map for the event - which is shown below as captured from their website at 12:30 AM on Monday, September 11th. This map shows the geographic pattern of intensity for the event.


Image by USGS

A more up-to-date reporting and map can be seen at the USGS Website.

Added: Looks like USGS is getting heavy web traffic from people checking on this event. Their earthquake server is up and down like a yo-yo tonight

Labels: Earthquakes

---

Image by USGS

A 6.0 magnitude earthquake occurred in the Gulf of Mexico at about 8:56 AM MDT today. The earthquake's location was about 330 miles southeast of New Orleans and about 250 miles west of Tampa, Florida. The focus was about 6.2 miles below sea level. No damages, injuries or tsunamis have been reported.

Image by USGS
Google Map -- Gulf of Mexico Earthquake

Shaking was felt in parts of Florida, Georgia, Alabama, Louisiana, Mississippi, Cuba and Mexico. The USGS reports:

"This is the largest of more than a dozen shocks that have been instrumentally recorded from the eastern Gulf of Mexico in the past three decades, and it is the most widely felt. The most recent significant earthquake in the region occurred on February 10th, 2006 and had a magnitude of 5.2. We have not associated this earthquake with a specific causative fault."

This is an unusual event because it is far removed from an active plate boundary. This location away from a plate boundary makes this type of earthquake unlikely to produce a tsunami. In addition, earthquakes of 6.0 magnitude are generally considered too weak to yield a tsunami.

More information at the National Earthquake Information Center

Labels: Earthquakes

---

Large-scale events such as earthquakes, hurricanes and tsunamis are very hazardous to insurance companies because they can simultaneously trigger thousands of claims, each worth tens or hundreds of thousands of dollars. Major events can cause enormous damage to an insurer's bottom line - or even threaten the life of the company.

An article in the Alaska Journal explains that Allstate stopped writing earthquake insurance policies in March and this year will drop the coverage from the policies of thousands of customers. So, if you want earthquake insurance, call another company - and if you have Allstate insurance and feel that earthquake insurance is an important part of your coverage, it's time to go shopping.

Read the Alaska Journal earthquake insurance article.

Labels: Earthquakes

---

Image by USGS

California Earthquake: A light, 4.4M earthquake occurred in the Glen Ellen / Santa Rosa area on Wednesday night, shortly after 8:00 PM local time. There were no reports of serious injury or damage.

Cleveland Earthquakes: Numerous micro to minor earthquakes have been felt and/or recorded beneath Cleveland this year. Although no injuries or damage have resulted from these quakes their frequency is disturbing to businesses and citizens. A news item on the
Cleveland Earthquakes at Topics.net
provides some interesting perspectives from local people. From the article...

"Data indicates homeowners aren't making many changes to protect against the quakes. There is little evidence that many homeowners have made moves to buy earthquake insurance, said Gary Christy with the Westfield Group insurance. Nine percent of the Westfield-insured homes in Lake County have earthquake insurance."

I would buy the insurance if I lived there.

Labels: Earthquakes

---

Image by USGS

A major earthquake (magnitude 7.7) south of Java Island, Indonesia triggered a tsunami that has struck the southern shore of Java Island. The wave was approximately two meters high on the Pangandaran shoreline area of Java. At least 50 people have been killed and hundreds missing and injured.

This earthquake is a result of thrust-faulting on the boundary between the Australia and Sunda Plates. Here the Australia Plate is moving north-northeast at about 6 centimeters per year relative to the Sunda Plate. It underthrusts the Sunda Plate at the Java Trench.


Image Copyright by Geology.com and Map Resources.
Read more about what causes a tsunami?.

Labels: Earthquakes, Tsunamis

---

University of Alberta geologist Patrick Wu hypothesizes that glacial melting due to climate change could cause increased volcanic activity and earthquakes. His linkage between them is the reduction in pressure on land areas as the ice (which can be over 1 KM thick in areas of Greenland and Antarctica) melts, and an increase in pressure upon the sea floor as sea level rises.

Many geologists might doubt this relation, however, very broad areas will be exposed to these changes and locations teetering on the verge of eruption or release could be enabled. Alan Glazner of the University of North Carolina reports that he also sees linkages between climate change and volcanic activity. ""When you melt glacial ice, several hundred metres to a kilometre thick . . . you've decreased the load on the crust and so you've decreased the pressure holding the volcanic conduits closed."

Read the article "Climate change could cause earthquakes and volcanic eruptions" at K-LightFM.com

Labels: Earthquakes, Global-Warming, Volcanoes

---

The Magnitude 7.3 earthquake that struck Haicheng, China on February 4th, 1975 was successfully predicted by Chinese scientists. This prediction was accurate enough that evacuation orders were issued just hours before the ground shaking. Even though this prediction saved the lives of thousands, the details of how the prediction was accomplished were kept secret.

A new article on the Geotimes website explains that this prediction was recently confirmed as "legitimate", based upon access to recently declassified documents and interviews with scientists involved with the prediction process.

You can read the full details of the prediction in this month's issue of the Bulletin of the Seismological Society of America or read a summary titled: "Confirming a Chinese earthquake prediction" at the Geotimes website.

Labels: Earthquakes

---

A news post on the Nature.com website explains why some scientists believe that southern California may be due for a major earthquake. The idea is that strain has been building up within the San Andreas Fault system for over 200 years. During that time the strain has been accumulating instead of being released through earthquake activity, "creep" or transfer into other fault systems.

The San Andreas Fault is the boundary between the North American Plate and the Pacific Plate. These plates are moving past one another at a rate of about one inch per year. However, rocks in the fault zone are stuck due to friction. Energy accumulates within the rocks and is released when the rocks rupture and the plates suddenly slip past one another.

Yuri Fialko of Scripps Institution of Oceanography has lead this study, which used radar data from European Space Agency satellites and GPS ground measurements. He estimates that there is enough accumulated energy to produce a magnitude 8.0 earthquake if it is all released in a single event.


Image by USGSRead more about his Southern California Earthquake Study at Nature.com.

Labels: Earthquakes

---

Schools across the Philippines practiced earthquake safety procedures on June 19. Over one million students and teachers from 40,000 public schools participated. The Philippines has many active faults and experiences recurrent earthquakes so education and practice is a very good idea. It is an especially good idea to target schools for this preparedness as children are very vulnerable to earthquake injury.

Small earthquakes can be very dangerous to untrained children. In October 1992, Egypt was struck by a moderate-size earthquake. Over 100 children were killed by this earthquake even though the schools in which they died were not seriously damaged. These children were killed by the feet of their classmates in panic-stricken stampedes. A small amount of training and proper supervision may have been able to save many of these lives.

Read more about the Philippine Earthquake Drill at inq7.net.

Labels: Earthquakes

---

On May 3rd, a 7.9-magnitude earthquake near Tonga prompted tsunami warnings in New Zealand, American Samoa, and Fiji. Fortunately there were only minor injuries and damage from the earthquake and the 2 foot high tsunami that it generated.

Seismic waves produced by the earthquake traveled through the earth at about 7400 miles per hour and arrived at a water well near Christiansburg, Virginia (7200 miles away) in a little under an hour. These waves compressed and expanded fractures that intersect a USGS ground water monitoring well and caused the well to surge up and down for nearly an hour. The surging of less than six total inches can be seen on the hydrograph below.

This well has a history of teleseismic activity. In 1985 it surged about 7 feet in response to the magnitude 8 earthquake near Mexico City and surged again after the magnitude 9 Indonesia earthquake of December, 1994.


Image by USGSVisit the Water Level Monitoring Station for this well.

Labels: Earthquakes

---

April 18th is the 100th anniversary of the 7.8 magnitude San Francisco Earthquake, the most deadly earthquake in United States history. The epicenter was about two miles offshore and this earthquake caused extensive damage throughout the city. Landslides, liquifaction and breakage of utility lines were responsible for much of the damage. This earthquake was one of the first to strike a city with an extensive utility infrastructure. Broken gas lines were responsible for many severe fires and broken water lines rendered the most effective fire-fighting tools useless.


Testimony page from the National Archives - Herman Schussler, Chief Engineer - Spring Valley Water Works

Here are some of the top resources on the web if you would like to learn more about this event.

National Archives - Collection of Letters and Testimony Transcripts

SFGate.com - Collection of Articles

National Geographic - San Francisco's 1906 Quake: What If It Struck Today?

Labels: Earthquakes

---

The Hayward Fault cuts through densely populated parts of the San Francisco Bay Area. Over 2,000,000 people live within shaking distance of the Hayward and a large earthquake there could be one of the most damaging and deadly earthquakes in the history of the United States.

The Hayward Fault produced a 6.9 magnitude earthquake in 1868 and many geologists believe that it could well be the source of the next major U.S. earthquake. Tom Brocher, USGS seismologist says that the Hayward Fault is "locked and loaded and ready to fire at any time".


Image produced using stills from www.llnl.gov
Read an interesting Associated Press article about the Hayward Fault.

Labels: Earthquakes

---

USGS has released "Earthquake Science Explained: A series of ten short articles for students, teachers and families". This general interest publication was produced in response to the 100th anniversary of the San Francisco 1906 Earthquake. Most of the articles are general but some focus on San Franciso and the Bay Area. Article titles:

• The Earthquake Machine: What 1906 taught us about how earthquakes work
• Seismograms: Earthquake Fingerprints
• Find the Fault: Recognizing Active Faults
• Looking into the Past With Earthquake Trenches
• When Will the Next Big One Hit? How Do We Know?
• Liquefaction - When the Ground Flows
• Bay Area Tsunamis: Are We at Risk?
• An Earthquake Scientist in Action: Jessica Murray
• How Do We Make Buildings and Roads Safer?
• Putting Down Roots in Earthquake Country

Image by USGSThis Earthquake Articles booklet is a free download at the USGS website.

Labels: Earthquakes

---

January 26 is the 305th anniversary of the Magnitude 9.0 Cascadia Earthquake that occurred in 1700. This extremely powerful earthquake caused damage to Native American villages in the Vancouver Island area and a tsunami caused local destruction and swept across the Pacific, causing significant damage along the west coast of Japan. Stories of this event have been preserved by the native people of western Canada and a summary of this earthquake can be read at the Canada Geological Survey Commission website. Cascadia Earthquake Information

Labels: Earthquakes

---

Dan Morris of the Jackson Sun (Tennessee) has posted an article about the potential of a large earthquake in the Mississippi Valley - similar in size to the New Madrid earthquakes of 1811/1812. His article has some interesting historical information and current perspectives but the most valuable part of it is the "Earthquake Survival Tip Sheets". Each sheet contains essential survival guidance. Here's what you can learn about if you go to his article...

Tip Sheet #1: Does your household have an earthquake plan?

Tip Sheet #2: What should I do during an earthquake?

Tip Sheet #3: What should I do immediately after an earthquake?

Tip Sheet #4: What should I do if I need medical attention?

Read the full text of his Earthquake Survival Tip Sheets at the JacksonSun.com website.

Labels: Earthquakes

---

USGS and the Geological Survey of Japan have prepared a report that ties a tsunami disaster that struck Japan in 1700 with an earthquake in the Cascadia Subduction Zone of North America. Here is a quote from a USGS news release about this report:

At approximately 9 p.m., January 26, 1700, a gigantic earthquake ripped across the west coast of Canada and the United States along the Cascadia Subduction Zone, more than 600 miles from Vancouver Island to Cape Mendecino. The magnitude of the earthquake ranged from 8.7 to 9.2. At that time there was no written documentation of the event, however, the large tsunami it triggered hit Japan approximately 10 hours later, and that information was recorded. Learn more about what USGS scientists and the Geological Survey of Japan have learned after meticulously researching this event.

Image by USGSRead the report: The Orphan Tsunami of 1700—Japanese Clues to a Parent Earthquake in North America

Labels: Earthquakes

---

USGS has shown that the 3D structure of the Earth has a significant impact on how strongly an earthquake is felt at different locations. They have employed earthquake fault maps and seismic data to produce the "3D Geologic and Seismic Velocity Model of the San Francisco Bay Region". This model is based upon the idea that the amount of ground shaking at a site depends on the local rock formations, soil conditions, and the subsurface structure along the path of the seismic waves.

Important applications of the model include:

• Forecasting strong ground motions that may damage buildings and essential infrastructure or destroy levees in the Sacramento Delta
• Predicting where destructive liquefaction of the ground may occur
• Locating earthquakes more accurately
• Defining the extent of groundwater aquifers and modeling of subsurface transport of contaminants

Image by USGS
Learn more about 3D Earthquake Fault Maps and Modeling at the USGS website.

Labels: Earthquakes, Maps

---

Geotimes has posted a Web Extra on the November 15th earthquake that occurred about 350 kilometers east of the island of Honshu, Japan. This earthquake had a magnitude of approximately 7.0 and generated a small tsunami. Author, Naomi Lubick, provides quotes from several earthquake experts related to this event and why a small tsunami was generated.
   
Images by USGSRead more at the Honshu Earthquake Web Extra.

Labels: Earthquakes

---

Computer models developed by UC Davis seismology experts have estimated the probability of a large earthquake in northern California. Their model suggests that a magnitude 7 earthquake along the San Andreas Fault within 150 miles of San Francisco has a 25% chance of occurring within the next two decades.



Read more about the Northern California Earthquake Outlook at SFGate.com.

Labels: Earthquakes

---

The BBC has some of the most detailed coverage of the Pakistan earthquake that can be found on the web. Extensive photos, eyewitness reports, and more.

Visit the BBC website for Pakistan Earthquake Photos and News.

Labels: Earthquakes

---

The United Nations Secretary General, Kofi Annan, has called for an "immediate and exceptional escalation" of assistance for Pakistan earthquake victims. Some experts have stated that the need for assistance with the Pakistan earthquake exceeds that of the Indonesia tsunami.

Delivery of aid has been very challenging because of the remote location, difficult access and earthquake damage to road systems. Fast aid is also needed because approximately 3,000,000 people are without shelter, sleeping in the open and cold winter weather starting to arrive.



Read more about the need for Pakistan Earthquake Relief at the United Nations Website.

Labels: Earthquakes

---

A major earthquake occurred about 60 miles (95 km) north-northeast of Islamabad, Pakistan at approximately 8:50 AM local time. Preliminary magnitude is 7.6 and the event has been followed by several strong aftershocks of 5+ and 6+ magnitude.



Images by USGSRead more about this Major Earthquake in Pakistan at the National Earthquake Information Center website and see early news coverage at MSN.com.

Labels: Earthquakes

---

A major earthquake has occurred in the New Ireland Region of Papua New Guinea. Preliminary estimates by USGS give this earthquake Magnitude 7.7. The Pacific Tsunami Warning Center has issued the following...

"NO DESTRUCTIVE PACIFIC-WIDE TSUNAMI THREAT EXISTS BASED ON HISTORICAL EARTHQUAKE AND TSUNAMI DATA.

HOWEVER - EARTHQUAKES OF THIS SIZE SOMETIMES GENERATE LOCAL TSUNAMIS THAT CAN BE DESTRUCTIVE ALONG COASTS LOCATED WITHIN A HUNDRED KILOMETERS OF THE EARTHQUAKE EPICENTER. AUTHORITIES IN THE REGION OF THE EPICENTER SHOULD BE AWARE OF THIS POSSIBILITY AND TAKE APPROPRIATE ACTION."

Images by USGSGet more details about this earthquake near Papua New Guinea at the National Earthquake Information Center.

Labels: Earthquakes

---

The USGS has a great website that features the sounds of several earthquakes, explains how the sound files were created, and provides information about how the sounds can be interpreted. Sound files for several earthquakes are provided: 1992 Magnitude 7.3 Landers Earthquake, 1992 Petrolia (near Eureka) Earthquakes, 1994 Magnitude 5 Parkfield Earthquake, Magnitude 2 Parkfield Earthquake.

Sounds from the 1992 Landers, California Earthquake

Listen to more at the USGS Earthquake Sounds website.

Labels: Earthquakes

---

What does an earthquake sound like? Researchers at Columbia University's Lamont-Doherty Earth Observatory have prepared a sound file for the December 26th, 2004 earthquake - the earthquake that generated the devastating tsunami. Sound recordings from the International Monitoring System of the Comprehensive Nuclear Test Ban Treaty were made avaiable to the Lamont-Doherty researchers and they have posted a refined sound file that you can hear on an MP3 player.
Visit their website to hear the Earthquake Sounds.

Labels: Earthquakes

---

Researchers at Delft University of Technology have created an animation that visually displays several elements of motion for the December 26, 2004 Earthquake. This earthquake occurred over a ten minute time interval. The animation shows the following.... 1) the progression of fault rupture across several hundred kilometers of seafloor, 2) propagation of the seismic surface waves, and 3) displacement of a few dozen GPS monitoring stations show large scale plate motions over the ten minute duration of the earthquake. This animation is worth watching and will make you realize that earthquake motion is not confined to a single point at the focus. View the Tsunami Earthquake Animation and more interesting graphics at the Delft University of Technology website.

Available on geology.com are two articles: What Causes a Tsunami? and Indonesia Tsunami Maps.

Labels: Earthquakes, Tsunamis

---

A major earthquake occurred on June 14th (local date), 2005 off the coast of northern California. The 7.0 magnitude earthquake prompted a tsunami watch, which was quickly lifted, and some precautionary evacuations in the Crescent City area. Read more about the California Earthquake at the USGS website.

Image from USGS

Labels: Earthquakes

---

A major earthquake occurred on June 13th, 2005 in the Tarapaca, Chile region. Read more about the Tarapaca,
Chile Earthquake.

Labels: Earthquakes

---

The USGS Earthquake Information Center is now posting real-time earthquake hazard maps on their website. These are updated every hour and show the probability of strong ground shaking for the state of California.

Labels: Earthquakes

---