April 17, 2016 - ARIZONA, UNITED STATES - Arizona could face the most dangerous fire season in years, according to Gov. Doug Ducey and the state's chief forester.
And it's already starting.
"Last year, we burned less than 500 acres" by this time,said Jeff Whitney. "So far this year we've burned over 21,000 acres."
And it's not looking promising.
"Arizona faces a potentially significant wildfire season," the governor said after he had been briefed by Whitney and his staff.
It starts with the fact that there have not been major fires in the last
two years. Add to that above-average rainfall and the subsequent growth
of vegetation - which is now drying out.
Pinion Pine Fire Chief Joe Jackson said the Hualapai Mountains have seen significant moisture this year.
The upside is, the ground remains damp.
The downside is, the grasses that have grown thanks to rain and snowfall will eventually dry out, said Jackson.
The moisture has not been substantial enough to add more fuels than usual, said Jackson.
"We always have concerns with fuels," said Jackson. "The grass is growing from the rains and that will help carry fire."
The last big fire to erupt in the Hualapai Mountains was the
Dean Peak Fire in the summer of 2013. Thousands of acres burned and the
Pinion Pine subdivision and other residential areas were threatened.
Jackson said his firefighters constantly train in wildland firefighting
and just recently helped put down the Topock Fire that burned more than
2,200 acres in the Lake Havasu National Wildlife Refuge. That fire
jumped the Colorado River and burned acreage in San Bernardino County.
Pinion Pine crews also helped battle a blaze near Parker in La Paz
County.
"We've done a lot of readiness training," said Jackson.
The high number of tourists in the state in the middle of the fire
season "also equals more opportunity for wildland fire," Ducey said.
"We sort of look for patterns," Whitney explained in how he makes the
annual predictions. And he conceded that conditions now are very similar
to 2002 and 2011.
That is a particularly significant conclusion.
In 2002, the Rodeo-Chedeski Fire burned about 468,000 acres. And the 2011 Wallow Fire consumed more than 538,000 acres.
"We remember those years and the fires we were on in those years,"
Whitney said. Then, turning to his map of predictions for this year, he
added, "I'm concerned about that."
Whitney acknowledged that one perennial issue is when to fight fires and when to simply try to contain them.
He said the debate goes back to the beginning of the 20th century over
whether to simply let fires "operate as a natural agent in the
ecosystem."
Whitney said the decision pretty much was made when there were large fires at the same time in Washington, Montana and Idaho.
"The policy then became the 10 a.m. policy, where every wildfire was
supposed to be suppressed no later than 10 a.m. the following day," he
explained. "We got so successful at that we created a fuels problem."
He said the goal now is to find a balance and find times "to allow fire
to operate more naturally to do some of the work that we need to have it
do for us."
But Whitney said that has to be governed when it's "ecologically appropriate." There has to be an assessment of risk.
"We've got some phenomenally predictive tools these days," he said. "If
we look at a fire and say, 'You know what? It's going to get hotter and
drier and the wind's going to blow up here in about three days,' and
it's kind of locked in the gun sights of Pine-Strawberry or Payson or
Flagstaff or the Williams watershed, we've got to go get it."
- Daily Miner.
April 17, 2016 - JAPAN - Researchers have found a long tear in the earth near the epicenter of a strong earthquake that jolted the southern Japanese prefecture of Kumamoto early Saturday.
They believe the scattering of cracks, which start on a road and run
into a rice paddy, trace the line of a fault that caused the tremor.
Hiroshima University Professor Emeritus Takashi Nakata and his team have
been examining the area around Mashiki Town since the magnitude-7.3
earthquake.
They found the deviation that runs through a rice paddy is about 1.2
meters wide. The earth on one side of the line is elevated by 50
centimeters.
On the road next to the paddy, the biggest crack is 2 meters
wide. The height difference between the ground on each side is 70
centimeters.
The researchers say the Futagawa and Hinagu faults both run through the area.
Nakata says a government panel of seismologists had expected that faults
in the area would slip by up to 2 meters (6.56 feet). He said the scale of the
Saturday earthquake was nearly as big as the panel's estimate.
WATCH: Researchers find slip in ground near quake epicenter in Japan.
April 17, 2016 - TONGA - A 5.8-magnitude has hit the coast of the Pacific island nation of Tonga,
USGS reported. The tremor with a depth of 66km, struck 287km from the
county's capital of Nuku'alofa.
The part of the South Pacific Ocean where Tonga lies is considered to be
one of the most seismically active areas in the world due to
convergence between the Australia and Pacific plates, the USGS said.
USGS shakemap intensity.
In March, a 6.2-magnitude earthquake struck off Tonga and the Samoa
islands, Geoscience Australia and the US Geological Survey (USGS)
reported. The quake occurred just 96km from the town of Hihifo in Tonga.
Seismotectonics of the Eastern Margin of the Australia Plate
The
eastern margin of the Australia plate is one of the most sesimically
active areas of the world due to high rates of convergence between the
Australia and Pacific plates. In the region of New Zealand, the 3000 km
long Australia-Pacific plate boundary extends from south of Macquarie
Island to the southern Kermadec Island chain. It includes an oceanic
transform (the Macquarie Ridge), two oppositely verging subduction zones
(Puysegur and Hikurangi), and a transpressive continental transform,
the Alpine Fault through South Island, New Zealand.
Since
1900 there have been 15 M7.5+ earthquakes recorded near New Zealand.
Nine of these, and the four largest, occurred along or near the
Macquarie Ridge, including the 1989 M8.2 event on the ridge itself, and
the 2004 M8.1 event 200 km to the west of the plate boundary, reflecting
intraplate deformation. The largest recorded earthquake in New Zealand
itself was the 1931 M7.8 Hawke's Bay earthquake, which killed 256
people. The last M7.5+ earthquake along the Alpine Fault was 170 years
ago; studies of the faults' strain accumulation suggest that similar
events are likely to occur again.
North of New
Zealand, the Australia-Pacific boundary stretches east of Tonga and Fiji
to 250 km south of Samoa. For 2,200 km the trench is approximately
linear, and includes two segments where old (greater than 120 Myr)
Pacific oceanic lithosphere rapidly subducts westward (Kermadec and
Tonga). At the northern end of the Tonga trench, the boundary curves
sharply westward and changes along a 700 km-long segment from
trench-normal subduction, to oblique subduction, to a left lateral
transform-like structure.
USGS plate tectonics for the region.
Australia-Pacific convergence rates
increase northward from 60 mm/yr at the southern Kermadec trench to 90
mm/yr at the northern Tonga trench; however, significant back arc
extension (or equivalently, slab rollback) causes the consumption rate
of subducting Pacific lithosphere to be much faster. The spreading rate
in the Havre trough, west of the Kermadec trench, increases northward
from 8 to 20 mm/yr. The southern tip of this spreading center is
propagating into the North Island of New Zealand, rifting it apart. In
the southern Lau Basin, west of the Tonga trench, the spreading rate
increases northward from 60 to 90 mm/yr, and in the northern Lau Basin,
multiple spreading centers result in an extension rate as high as 160
mm/yr. The overall subduction velocity of the Pacific plate is the
vector sum of Australia-Pacific velocity and back arc spreading
velocity: thus it increases northward along the Kermadec trench from 70
to 100 mm/yr, and along the Tonga trench from 150 to 240 mm/yr.
The
Kermadec-Tonga subduction zone generates many large earthquakes on the
interface between the descending Pacific and overriding Australia
plates, within the two plates themselves and, less frequently, near the
outer rise of the Pacific plate east of the trench. Since 1900, 40 M7.5+
earthquakes have been recorded, mostly north of 30°S. However, it is
unclear whether any of the few historic M8+ events that have occurred
close to the plate boundary were underthrusting events on the plate
interface, or were intraplate earthquakes. On September 29, 2009, one of
the largest normal fault (outer rise) earthquakes ever recorded (M8.1)
occurred south of Samoa, 40 km east of the Tonga trench, generating a
tsunami that killed at least 180 people.
Across the
North Fiji Basin and to the west of the Vanuatu Islands, the Australia
plate again subducts eastwards beneath the Pacific, at the North New
Hebrides trench. At the southern end of this trench, east of the Loyalty
Islands, the plate boundary curves east into an oceanic transform-like
structure analogous to the one north of Tonga.
Australia-Pacific
convergence rates increase northward from 80 to 90 mm/yr along the
North New Hebrides trench, but the Australia plate consumption rate is
increased by extension in the back arc and in the North Fiji Basin. Back
arc spreading occurs at a rate of 50 mm/yr along most of the subduction
zone, except near ~15°S, where the D'Entrecasteaux ridge intersects the
trench and causes localized compression of 50 mm/yr in the back arc.
Therefore, the Australia plate subduction velocity ranges from 120 mm/yr
at the southern end of the North New Hebrides trench, to 40 mm/yr at
the D'Entrecasteaux ridge-trench intersection, to 170 mm/yr at the
northern end of the trench.
Large earthquakes are
common along the North New Hebrides trench and have mechanisms
associated with subduction tectonics, though occasional strike slip
earthquakes occur near the subduction of the D'Entrecasteaux ridge.
Within the subduction zone 34 M7.5+ earthquakes have been recorded since
1900. On October 7, 2009, a large interplate thrust fault earthquake
(M7.6) in the northern North New Hebrides subduction zone was followed
15 minutes later by an even larger interplate event (M7.8) 60 km to the
north. It is likely that the first event triggered the second of the
so-called earthquake "doublet".
April 17, 2016 - ECUADOR - At least 77 people have been killed after a 7.8-magnitude earthquake hit Ecuador's central coast.
Tremors were recorded at 11:58 p.m. UTC time (02:58 MSK). According to
the USGS, the epicenter of the quake was 17 miles away from the coastal
town of Muisne and just over 100 miles away from the capital Quito.
Hazardous tsunami waves of up to one meter (3.2 feet) above the tide
level are possible in Ecuador, the Pacific Tsunami Warning Center (PTWC)
said in a forecast after a powerful earthquake shook the coast of the
country.
USGS shakemap intensity.
"Tsunami waves reaching 0.3 to 1 meters above the tide level are
possible for some coasts of Ecuador," the PTWC said in a statement.
Officials have declared a state of emergency in six of the country's 24
provinces and the National Guard. The tremor destroyed homes and
collapsed one major overpass.
President Rafael Correa urged the country's 16 million people to remain calm during the crisis.
"Our infinite love to the families of the dead," he said on Twitter. He
also announced that he would cut short his trip to Italy to return home.
Vice President Jorge Glas also announced that the number of injured
people were not currently available but he admitted that the death toll
is expected to rise.
"This
wasn't just a house that collapsed, it was an entire town."
On social media residents shared photos of homes collapsed, the roof of a
shopping centre coming apart and supermarket shelves shaking violently.
In Manta, the airport was closed after the control tower collapsed,
injuring an air force official. Hydroelectric dams and oil pipelines in
the OPEC-member nation were shut down as a precautionary measure.
WATCH: Monumental Earth Changes.
Zoila Villena, a Quito resident said that she is in a current "state of panic."
"My building moved a lot and things fell to the floor," Villena told The
Associated Press.
"Lots of neighbors were screaming and kids crying."
The US Geological Survey said the shallow quake, the strongest since
1979 to hit Ecuador, was centred on south-southeast of Muisne, a
sparsely populated area of fishing ports that is popular with tourists.
USGS Tectonic Summary
The April 16, 2016 M 7.8 earthquake, offshore of the west coast of
northern Ecuador, occurred as the result of shallow thrust faulting on
or near the plate boundary between the Nazca and Pacific plates. At the
location of the earthquake, the Nazca plate subducts eastward beneath
the South America plate at a velocity of 61 mm/yr. The location and
mechanism of the earthquake are consistent with slip on the primary
plate boundary interface, or megathrust, between these two major plates.
Subduction along the Ecuador Trench to the west of Ecuador, and the
Peru-Chile Trench further south, has led to uplift of the Andes mountain
range and has produced some of the largest earthquakes in the world,
including the largest earthquake on record, the 1960 M 9.5 earthquake in
southern Chile.
While commonly plotted as points on maps, earthquakes of this size are
more appropriately described as slip over a larger fault area. Events of
the size of the April 16, 2016 earthquake are typically about 160x60 km
in size (length x width).
Ecuador has a history of large subduction zone related earthquakes.
Seven magnitude 7 or greater earthquakes have occurred within 250 km of
this event since 1900. On May 14th, 1942, a M 7.8 earthquake occurred 43
km south of this April 16th, 2016 event. On January 31st, 1906 a M 8.3
earthquake (reportedly as large as M 8.8 in some sources) nucleated on
the subduction zone interface 90 km to the northeast of the April 2016
event, and ruptured over a length of approximately 400-500 km, resulting
in a damaging tsunami that caused in the region of 500-1,500
fatalities. The April 2016 earthquake is at the southern end of the
approximate rupture area of the 1906 event. A shallow, upper crustal M
7.2 earthquake 240 km east of the April 2016 event on March 6th, 1987
resulted in approximately 1,000 fatalities.
USGS Seismotectonics of South America (Nazca Plate Region)
The
South American arc extends over 7,000 km, from the Chilean margin
triple junction offshore of southern Chile to its intersection with the
Panama fracture zone, offshore of the southern coast of Panama in
Central America. It marks the plate boundary between the subducting
Nazca plate and the South America plate, where the oceanic crust and
lithosphere of the Nazca plate begin their descent into the mantle
beneath South America. The convergence associated with this subduction
process is responsible for the uplift of the Andes Mountains, and for
the active volcanic chain present along much of this deformation front.
Relative to a fixed South America plate, the Nazca plate moves slightly
north of eastwards at a rate varying from approximately 80 mm/yr in the
south to approximately 65 mm/yr in the north. Although the rate of
subduction varies little along the entire arc, there are complex changes
in the geologic processes along the subduction zone that dramatically
influence volcanic activity, crustal deformation, earthquake generation
and occurrence all along the western edge of South America.
Most
of the large earthquakes in South America are constrained to shallow
depths of 0 to 70 km resulting from both crustal and interplate
deformation. Crustal earthquakes result from deformation and mountain
building in the overriding South America plate and generate earthquakes
as deep as approximately 50 km. Interplate earthquakes occur due to slip
along the dipping interface between the Nazca and the South American
plates. Interplate earthquakes in this region are frequent and often
large, and occur between the depths of approximately 10 and 60 km. Since
1900, numerous magnitude 8 or larger earthquakes have occurred on this
subduction zone interface that were followed by devastating tsunamis,
including the 1960 M9.5 earthquake in southern Chile, the largest
instrumentally recorded earthquake in the world. Other notable shallow
tsunami-generating earthquakes include the 1906 M8.5 earthquake near
Esmeraldas, Ecuador, the 1922 M8.5 earthquake near Coquimbo, Chile, the
2001 M8.4 Arequipa, Peru earthquake, the 2007 M8.0 earthquake near
Pisco, Peru, and the 2010 M8.8 Maule, Chile earthquake located just
north of the 1960 event.
USGS plate tectonics for the region.
Large
intermediate-depth earthquakes (those occurring between depths of
approximately 70 and 300 km) are relatively limited in size and spatial
extent in South America, and occur within the Nazca plate as a result of
internal deformation within the subducting plate. These earthquakes
generally cluster beneath northern Chile and southwestern Bolivia, and
to a lesser extent beneath northern Peru and southern Ecuador, with
depths between 110 and 130 km. Most of these earthquakes occur adjacent
to the bend in the coastline between Peru and Chile. The most recent
large intermediate-depth earthquake in this region was the 2005 M7.8
Tarapaca, Chile earthquake.
Earthquakes can also be
generated to depths greater than 600 km as a result of continued
internal deformation of the subducting Nazca plate. Deep-focus
earthquakes in South America are not observed from a depth range of
approximately 300 to 500 km. Instead, deep earthquakes in this region
occur at depths of 500 to 650 km and are concentrated into two zones:
one that runs beneath the Peru-Brazil border and another that extends
from central Bolivia to central Argentina. These earthquakes generally
do not exhibit large magnitudes. An exception to this was the 1994
Bolivian earthquake in northwestern Bolivia. This M8.2 earthquake
occurred at a depth of 631 km, making it the largest deep-focus
earthquake instrumentally recorded, and was felt widely throughout South
and North America.
Subduction of the Nazca plate is
geometrically complex and impacts the geology and seismicity of the
western edge of South America. The intermediate-depth regions of the
subducting Nazca plate can be segmented into five sections based on
their angle of subduction beneath the South America plate. Three
segments are characterized by steeply dipping subduction; the other two
by near-horizontal subduction. The Nazca plate beneath northern Ecuador,
southern Peru to northern Chile, and southern Chile descend into the
mantle at angles of 25° to 30°. In contrast, the slab beneath southern
Ecuador to central Peru, and under central Chile, is subducting at a
shallow angle of approximately 10° or less. In these regions of
“flat-slab” subduction, the Nazca plate moves horizontally for several
hundred kilometers before continuing its descent into the mantle, and is
shadowed by an extended zone of crustal seismicity in the overlying
South America plate. Although the South America plate exhibits a chain
of active volcanism resulting from the subduction and partial melting of
the Nazca oceanic lithosphere along most of the arc, these regions of
inferred shallow subduction correlate with an absence of volcanic
activity. -
