San Andreas Fault Predicted To Trigger Strong Los Angeles Earthquake

Scientists at Stanford University used underground ambient seismic waves to predict that Los Angeles will experience a strong and large ground movements if an earthquake occurs along the southern San Andreas Fault, near the Salton Sea.

The Stanford scientists used weak vibrations under the Earth's core to measure and follow the movement of seismic waves. These waves are produced by the ocean waves crashing into the Earth's core. Although billions of times weaker than seismic waves generated by earthquakes, these ambient waves still follow the path an earthquake wave would.

Based on their measurements, an earthquake generated seismic waves will be funneled toward Los Angeles if the southern San Andreas Fault section of California were to experience an earthquake.

The scientists further predict that the seismic waves will be futher amplified when it reaches Los Angeles because the city sits atop a large sedimentary basin.

Earthquake Lights (EQL) Associated With Rift Environments and Subvertical Faults

Earthquake lights (EQL) photographed in Tagish Lake, Yukon-Alaska border region. Lights were estimated at 1 meter in diameter with the closest orbs slowly drifting up the mountain to join the more distant ones.
Credit: Jim Conacher

A study suggests that earthquake lights (EQL) have a higher probability of occurring on or near rift environments where subvertical faults allow stress-induced electrical currents to flow rapidly to the surface.

Earthquake lights are mysterious lights that appear before or during an earthquake. They appear in different shapes and forms such as spheres of light floating through the air (as imaged on the left), high flames of light, multi-colored globes of light moving through the sky, or just streams of light running along the ground.

Earthquake lights are rarely seen after an earthquake. This suggests that the nature of these lights could be based on the stress mechanics exerted on the faults during an earthquake. Of the documented occurrences of earthquake lights, the study shows that 97% of these have been associated with rift environments.

A rift is a linear zone where the Earth's crust and the hard and rigid outer layer of the Earth, called the lithosphere, are being pulled apart. This forms an extensive system of fractures and faults. Only 5% of seismic activity are associated with this type of intraplate seismic activity which also can explain the rare occurence of earthquake lights.

Using Particle Physics and Geo-Electrons To Probe The Deep Layers of The Earth

The picture depicts the long-range spin-spin interaction (blue wavy lines) in which the spin-sensitive detector on Earth’s surface interacts with geoelectrons (red dots) deep in Earth’s mantle. The arrows on the geoelectrons indicate their spin orientations, opposite that of Earth’s magnetic field lines (white arcs).
Credit: Marc Airhart (University of Texas at Austin) and Steve Jacobsen (Northwestern University).

Researchers have come up with a new technique using particle physics and geo-electrons to find out in great detail what the deep layers of the Earth is made up of and how it behaves.

Scientists for a long time have been trying to understand more about the Earth's core. The surface of the Earth is known as the crust and is around 10 kilometers thick at its thinnest. Below the crust is the mantle and between the mantle and the inner core, it is around 3,000 kilometers. It is impossible by current technologies to even drill past the crust.

In November 2011, Japanese scientist Kei Hirose, used a particle accelerator (the Spring-8 Synchrotron) to recreate the conditions believed to exist at the Earth's core. The experiment suggests that the core is made up of a forest of huge crystals 10 kilometers tall.

Other techniques used to study the Earth's inner layers are by studying the vibrations caused by earthquakes, using x-rays and other imaging techniques, or by mimicking the temperatures and pressures of the deep Earth in laboratories.

Now, researchers from Amherst College and The University of Texas at Austin have developed another technique to solve this geological mystery not by recreating the conditions but by studying electrons found in mantle minerals called geoelectrons.

Massive Earthquakes And Their Relationship To Each Other

San Francisco Mission District burning in the aftermath of the San Francisco Earthquake of 1906.

One important aspect of an earthquake sequence is the clustering of earthquakes within an area in a duration of time. This is observed in both small scale and global levels.

Earthquake swarms or clusters are events where a local area experiences sequences of many earthquakes striking in a relatively short period of time. Most earthquakes, except possibly the strongest ones, come in clusters. Earhquakes consists of one main shock and the resulting aftershocks, there are even events of multiple earthquakes clustered so densely that they are considered as a single event.

The phenomena of clustering has been garnering attention due to the recent spate of earthquakes in the last decade. It has increased recently when it was noticed that unusually large clusters of earthquakes often occur after a strong earthquake. However, the mechanism of clustering is not clear and presents an important problem due to its intrinsic connection with one of the unexplained fundamental features of earthquakes-their interaction with each other over wide distances and time intervals.

Are large earthquakes linked across the globe?

The past decade has been plagued with what seems to be a cluster of large earthquakes, with massive quakes striking Sumatra, Chile, Haiti and Japan since 2004. Some researchers have suggested that this cluster has occurred because the earthquakes may be "communicating" across large distances, possibly triggering each other. But a new analysis by Tom Parsons and Eric Geist of the US Geological Survey concludes that the cluster could just as well be the result of random chance.

Each of the devastating quakes in the 2000s drew huge media coverage and required extensive rebuilding and economic restoration. The intense interest in the earthquakes has led some to wonder if we are living in the middle of an "age of great quakes," similar to a global cluster of quakes in the 1960s. It's important to know whether these clusters occur because big earthquakes trigger others across the world, Parsons and Geist say, in order to predict whether more severely destructive quakes might be on the way.

Geological Data Suggest Greek Region Is Vulnerable To Tsunami Events

A tsunami is usually thought to be one giant wave. In actuality, it is a series of water waves, each bigger than the previous one. It is caused by the displacement of a large volume of a body of water, typically an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami.

On 26 December 2004, a devastating tsunami up to 98 feet high, hit the northern province Aceh of the island Sumatra. It is estimated that 230,000 people were killed.

Recently in Japan on 11 March 2011, a tsunami hit Miyako in Tōhoku's Iwate Prefecture. The tsunami which reached a height of 133 feet, caused a number of nuclear accidents, primarily the ongoing level 7 meltdowns at three reactors in the Fukushima Daiichi Nuclear Power Plant complex, and the associated evacuation zones affecting hundreds of thousands of residents. The confirmed death toll was at 15,840.

The largest recorded tsunami was a wave 1720 feet tall in Lituya Bay, Alaska on 09 July 1958. Millions of trees were uprooted along the bay but no casualties were reported.

Warning signs from ancient Greek tsunami

In the winter of 479 B.C., a tsunami was the savior of Potidaea, drowning hundreds of Persian invaders as they lay siege to the ancient Greek village. New geological evidence suggests that the region may still be vulnerable to tsunami events, according to Klaus Reicherter of Aachen University in Germany and his colleagues.

Earthquake Watch

As of 06 March 2012, 7:32 GMT, there have been 232 earthquakes in the last 7 days recorded by the US Geological Survey (USGS).

The Science and Physics of Earthquake Prediction

For years, scientists have been trying to predict when an earthquake will strike. They have been trying to find a way to predict one in terms of specific magnitude, place, and time or range of time. The closest that scientists have reached is to estimate whether a well observed fault line may rupture in the next few decades.

The study of plate tectonics have been around since the 1970s and yet, the factors and variables of earthquake predictions are still not very well understood. Based on current observations and belief, many phenomena are considered to be possible precursors of earthquakes, and among those under investigation are seismicity, changes in the ionosphere, various types of electromagnetic indicators including infrared and radio waves, radon emissions, and even unusual animal behavior.

One year on from the magnitude-9.0 earthquake that unleashed a devastating tsunami and caused a partial meltdown of the Fukushima Daiichi nuclear plant, this month's special issue of Physics World, on the theme of "Physics and the Earth", includes an investigation by journalist Edwin Cartlidge into the latest advances in earthquake forecasting.

The huge responsibility that comes with assessing the likelihood of earthquakes was never more evident than in March 2009, when a group of 11 Italian scientists met to discuss the risk of a powerful earthquake striking the town of L'Aquila, after a swarm of small quakes had hit the area continuously for four months.

After concluding that there were no grounds for alarm, a devastating magnitude-6.3 earthquake struck the town on 6 April that year, leaving 308 people dead. Now, seven of those 11 scientists are on trial for manslaughter.