U.S. hit by numerous earthquakes?

During the past decade from December 2004 to present, no less than 18 great (Mw ≥ 8.0) earthquakes occurred globally (~1.8 per year), compared to 71 from 1900 to mid-2004 (~0.68 per year), yielding an effective rate increase of 265%, says seismologist Thorne Lay of the University of California at Santa Cruz.

What about smaller earthquakes? As the image below illustrates, of the 1495 earthquakes that hit the world over a period of seven days up to October 17, 2014, 05:04:30, UTC, 1404 occured in the map area of the image below. However, the U.S. is over-represented, the USGS map doesn't show smaller earthquakes (under magnitude 4) outside the U.S.

[ click on image to enlarge ]

Can we expect more earthquakes to hit the U.S.? If so, why?

First of all, as said, many earthquakes do appear to hit the U.S. when looking at above image, but the above USGS map doesn't show smaller earthquakes (under magnitude 4) outside the U.S.

Nonetheless, there can be other reasons why so many earthquakes have recently hit the U.S., so let's explore some of them further.

It's a well-known phenemenon that, during the northern summer, more earthquakes do hit the Northern Hemisphere, rather than the Southern hemisphere. That's a natural phenomenon, but there can also be ways in which people can contribute to the incidence of earthquakes.

Isostatic rebound and changing stress conditions due to meltwater run-off can trigger seismic events. For months now, a huge amount of seismic activity has hit faultlines along the boundaries of the North American Plate, as earlier discussed in the earlier post Ring of Ice.

Bill McGuire, Emeritus Professor of Earth Sciences at the University College London, recently said the following in post at ClimateState.com:

“There may be a threat of submarine landslides around the margins of Greenland, which are less well explored. Greenland is already uplifting, reducing the pressure on the crust beneath and also on submarine methane hydrates in the sediment around its margins, and increased seismic activity may be apparent within decades as active faults beneath the ice sheet are unloaded. This could provide the potential for the earthquake or methane hydrate destabilisation of submarine sediment, leading to the formation of submarine slides and, perhaps, tsunamis in the North Atlantic.

We see evidence of the Earth ‘waking up’ specifically in relation to seismic activity in areas of Alaska where dramatic ice loss (up to 1km vertical thickness) has occurred over the last 100 years, and also in relation to the correlation in many high mountains terrains of increased landslide occurrence and heatwaves.

There is no unequivocal evidence for a specific volcanic response, unless the high level of recent activity at the Icelandic volcanoes is a reflection of unloading due to melting of the Vatnajokull Ice Cap. Certainly this whole region is uplifting by a few centimetres a year, so such a suggestion would not be completely unreasonable, even if we don’t (yet?) have any hard evidence.”

Particularly dangerous in this respect are earthquakes along the fault that crosses the Arctic Ocean, such as the 4.5 M earthquake indicated by the blue dot on the top map, also indicated on the map below. The danger here is that such earthquakes could destabilize methane hydrates that are highly prominent in sediments under the Arctic Ocean.

Map, created with methanetracker.org, with recent earthquakes on the northern boundery of the North American Plate
[click on image to enlarge]

As discussed in earlier posts, wild weather swings could also contribute to destabilization of methane hydrates. Furthermore, a study published this year suggests that human-caused groundwater depletion contributed to the prominence of earthquakes in California. Similar suggestions were made in a study focusing on a 2011 earthquake in Spain.

[ click on image to enlarge ]

Besides the above wild weather swings, wild weather itself could similarly be destructive. As hurricane Sandy approached the U.S. coast in 2012, the force of waves slamming into other waves shook the seafloor, which was recorded by earthquake sensors. The energy generated by Sandy was similar to small earthquakes between magnitudes 2 and 3, seismologists at the University of Utah estimated.

Did typhoon VongFong cause earthquakes around Japan? The image on the right shows earthquakes that occured around Japan during the seven days up to October 16, 2014. Again, the map doesn't show the smaller quakes, so further studies may be needed to shed more light on this.

[ click on image to enlarge ]

As above image shows, some 1500 earthquakes hit the world over a period of seven days up to October 17, 2014, 03:59:21, UTC. Of all these earthquakes, some 1300 hit the U.S. alone. This points at a further cause, i.e. fracking. A recent study has confirmed that fracking is linked to more earthquakes than previously believed.

“Earth to Obama . . .”

from: FAQs

Rob Howarth, Ph.D. and Professor of Ecology and Environmental Biology at Cornell University, comments:

“By once again failing to announce strong, decisive action to combat methane at the recent Climate Summit at the United Nations, Obama missed a major opportunity to demonstrate global leadership on climate change. Global emissions of methane equal or exceed the global emissions of carbon dioxide, when the methane emissions are converted to their equivalency for causing global warming using an integrated 10-year time period.”

Meanwhile, the EPA is still underreporting methane's Global Warming Potential, as earlier discussed at Myth #7 and despite a call by Rob Howarth and other methane experts to accurately account for warming effects of methane.

Update

Below is an updated map with more recent data, showing that over a period of 7 days up to October 18, 2014, 01:39:12 UTC, some 1400 earthquakes hit the U.S. Again, note that the USGS map doesn't show earthquakes under magnitude 4 outside the U.S.

References

- A global surge of great earthquakes from 2004-2014 amd implications for Cascadia - by Thorne Lay
https://gsa.confex.com/gsa/2014AM/webprogram/Paper242140.html

- Ring of Ice
http://arctic-news.blogspot.com/2014/08/ring-of-ice.html

- Methane hydrate destabilisation is clearly a real worry, particularly in the context of warming ocean waters in the East Siberian Continental Shelf
http://climatestate.com/2014/10/16/methane-hydrate-destabilisation-is-clearly-a-real-worry-particularly-in-the-context-of-warming-ocean-waters-in-the-east-siberian-continental-shelf

- Wild Weather Swings
http://arctic-news.blogspot.com/2014/10/wild-weather-swings.html

- Uplift and seismicity driven by groundwater depletion in central California
http://www.nature.com/nature/journal/v509/n7501/full/nature13275.html

- The 2011 Lorca earthquake slip distribution controlled by groundwater crustal unloading
http://www.nature.com/ngeo/journal/v5/n11/full/ngeo1610.html

- Superstorm Sandy's Energy Jolted U.S., Detected By Earthquake Sensors In Pacific Northwest
http://www.huffingtonpost.com/2013/04/18/superstorm-sandy-energy_n_3112814.html

- Sandy Shook US Like an Earthquake
http://www.livescience.com/24726-sandy-earthquake-movie.html

- Fracking Linked to More Ohio Earthquakes
http://www.livescience.com/48294-fracking-caused-ohio-earthquakes.html

- Characterization of an Earthquake Sequence Triggered by Hydraulic Fracturing in Harrison County, Ohio
http://srl.geoscienceworld.org/content/early/2014/10/09/0220140127.extract

- Climate change, Obama, and methane
http://thehill.com/blogs/congress-blog/energy-environment/219704-climate-change-obama-and-methane

Post by Sam Carana.

Ring Of Ice

Prominence of earthquakes in North America and around Greenland has prompted a team of researchers led by Arctic-news blog editor Sam Carana to coin the phrase “Ring Of Ice” to describe what they see happening in the Arctic.

“Melting of ice in north Canada and on Greenland is causing pressure changes, resulting in seismic activity”, explains Sam Carana.

Heavy seismic activity is ocurring along the faultlines that constitute the border of the North American Plate, similar to the the heavy activity along the Ring Of Fire around the Pacific Ocean.

Seismic activity roughly follows the borders of the North American Plate, which includes Greenland. However, where the major fault bends away to the west following the Aleutian Islands, seismic activity continues north through Alaska along a line that extends over the North Pole toward Svalbard.

This northward path through Alaska is illustrated by the earthquakes on the image below.

“Earthquakes are prominent along the entire border of the North American Plate”, Sam Carana adds, “but they increasingly appear to be taking this shortcut through Alaska and the underlying cause of this is melting of ice in north Canada and on Greenland”.

“This Ring Of Ice spells danger, just like the name Ring Of Fire indicates danger”, Sam Carana concludes. “The name Ring Of Fire warns about possible volcanoes, earthquakes, landslides and tsunamis. The Ring Of Ice seems even more dangerous, since seismic activity could destabilize methane hydrates contained in sediments under the Arctic Ocean, and could trigger huge methane eruptions. The fault line running from Greenland to Siberia is the most dangerous area on Earth in that respect”.

From the earlier post High Methane Levels over Laptev Sea

Post by Sam Carana.

The Arctic Methane Monster's Rapid Rise

Researcher Jennifer Hynes recently gave a frightening presentation about the situation in the Arctic and the odds that things will rapidly spiral out of control soon, escalating into runaway global warming a few decades from now. 

Above, a slide from the presentation, warning about the danger of earthquakes causing methane hydrate destabilization (from: Smoke Blankets North America). As the map below shows, 77 M4+ earthquakes did hit locations around Greenland in the year 2014 up until August 4.

Below is Jennifer's presentation, also on youtube at youtube.com/watch?v=a9PshoYtoxo



The image below shows sea surface temperature anomalies in the Arctic at August 7, 2014.

Warm water is carried into the Arctic Ocean by the Gulf Stream, as illustrated by the image below.

[ click on image to enlarge ]

The image shows how the Gulf Stream brings warm water to the edge of the sea ice. Waters close to Svalbard reached temperatures as high as 15.6°C (60.1°F) on August 8, 2014 (green circle). Note that what the image shows are sea surface temperatures only. At greater depths (say 300 m), warm water is pushed through the Greenland Sea by the Gulf Stream. Since the passage west of Svalbard is rather shallow, a lot of this warm water comes to the surface there. The high sea surface temperatures west of Svalbard thus indicate that the Gulf Stream is carrying very warm water (warmer than 15°C) at greater depths and is pushing this underneath the sea ice north of Svalbard.

As said, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog at climateplan.blogspot.com and as illustrated by the image below.

Post by Sam Carana.

Earthquakes and Warm Water threaten Arctic

[ soucre: NOAA image - click to enlarge]

A major earthquake hit the Aleutian Islands, Alaska, on June 23, 2014.

The earthquake occurred at 51.797°N 178.760°E, 15 miles (24 km) southeast of Little Sitkin Island, Alaska, at a depth of 66.8 miles (107.5km).

The U.S. Geological Survey (USGS) earlier listed the earthquake at a magnitude of 8 on the Richter scale, but eventually gave the quake a magnitude of 7.9.

Initial tsunami warnings, as reflected by the two NOAA images on the right, were later cancelled, e.g. the Pacific Tsunami Warning Center in Hawaii said the earthquake’s epicenter was too deep to pose a tsunami threat to its coasts.

Indeed, earthquakes that occur at less depth, i.e. closer to the seafloor, pose a greater tsunami threat, as more energy will enter the sea as kinetic energy pushing up wave height propelled in the form of a tsunami.

Earthquakes that occur at greater depth pose other kinds of threats. When earthquakes hit deep under the sea floor, more energy will translate into shockwaves that can propagate over great distances through the Earth crust, particularly along fault lines.

[ source: NOAA image - click to enlarge]

In this case, the situation is particularly threatening for the Arctic Ocean. As the map below shows, the fault line where this earthquake hit extends through Siberia into the Laptev Sea and was hit by three earthquakes recently:

M 4.9 - East of Severnaya Zemlya
2014-06-22 23:58:24 UTC
Location 78.520°N 125.942°E
Depth 10.00 km (6.21 mi)

M 4.7 - Laptev Sea
2014-06-01 08:52:43 UTC
Location 75.012°N 133.665°E
Depth 10.00 km (6.21 mi)

M 4.8 - 172km N of Deputatskiy, Russia
2014-05-29 05:07:33 UTC
Location 70.844°N 139.761°E
Depth 10.00 km (6.21 mi)

A cluster of earthquakes that recently hit the Aleutian Islands shows up in green in the top right corner op above map. Also note the red dot on the right, respresenting a M 4.1 earthquake that hit the Sea of Okhotsk on June 22, 2014 (at 09:47:47 UTC, location 51.843°N 151.310°E), at a depth of 527.66 km (327.87 mi).

Earthquakes are a major threat for the Arctyic as they can destabilize methane hydrates contained in sediments under the seafloor of the Arctic Ocean.

The situation is the more dangerous given the warm sea water that threatens to enter the Arctic Ocean, as illustrated by the image below.

As the recent NOAA overview of the climate situation in May 2014 describes, combined average temperature over global land and ocean surfaces reached a record high for May, at 0.74°C (1.33°F) higher than the 20th century average. Across the oceans, the global monthly-averaged sea surface temperature was 0.59°C (1.06°F) higher than the 20th century average, marking the highest May temperature on record. This is further illustrated by the image below.

Meanwhile, the situation hasn't improved, as illustrated by the image below.

The NOAA image below shows sea surface temperature anomalies in the Arctic Ocean on June 23, 2014, with many areas showing anomalies above 8 degrees Celsius.



According to NOAA's Climate Prediction Center, there is about a 70% chance that El Niño conditions will develop during the Northern Hemisphere summer 2014 and an 80% chance it will develop a few months later.

As discussed in earlier posts, the sea ice is already very thin, and while ocean heat is melting the sea ice from beneath, the sun is warming up the ice from above. At this time of year, insolation in the Arctic is at its highest, as Earth reaches its maximum axial tilt toward the sun of 23° 26'. In fact, insolation during the months June and July is higher in the Arctic than anywhere else on Earth, as discussed at this earlier post.

Feedbacks further accelerate warming in the Arctic, as described in the earlier post Feedbacks in the Arctic. Temperature rises of the water close to the seafloor of the Arctic Ocean is very dangerous, as heat penetrating sediments there could cause hydrate destabilization, resulting in huge amounts of methane entering the atmosphere over the Arctic Ocean.

In conclusion, the situation is the Arctic is threatening to escalate into runaway warming and urgently requires comprehensive and effective action as discussed at the Climate Plan blog.