Chilean National Service of Geology and Mining - SERNAGEOMIN and its Volcano Observatory Southern Andes (OVDAS) raised the alert level of Copahue volcano from Yellow to Orange. The latest activity is compared to that of December 2012.
In a report released on May 23, 2013, they state that there has been an increase in seismic activity at all stations monitoring Copahue volcano since May 15th. Emissions of gas and ash have also been observed. The largest earthquake occurred on May 18, with a local magnitude (ML) 2.9, located approximately 6 km to the east of the main crater.
Observed events indicate a possibility of new magmatic intrusion on its way. This scenario is confirmed by the start of small ash emissions and glow at the crater which is visible at night.
An earthquake of preliminary magnitude 6.5 struck today off the coast of Chile, according to the U.S. Geological Survey (USGS).
The temblor’s epicenter was 367 miles (590 km) west-southwest of Puerto Quellon and 952 miles (1532 km) south-southwest of the capital, Santiago. It originated 6.2 miles (10 km) deep and struck at 4:49 a.m. (9:49 UTC), the USGS reports.
No tsunami warning was issued and the quake was not felt on land, according to the Associated Press.
Chile’s coastline is a seismic hotspot along the very active Pacific “Ring of Fire” thanks to a subduction zone where one plate of Earth’s crust dives under another. In 1960, a magnitude 9.5 earthquake, the largest ever recorded, struck in southern Chile. It killed more than 1,600 people in South America, unleashing a tsunami that crossed the Pacific and killed 61 people in Hawaii, Japan, and the Philippines. More recently, a violent magnitude 8.8 earthquake in February 2010 killed more than 500 people, damaged or destroyed thousands of buildings, raised the coastline, and even moved the city of Concepción 10 feet (3 meters) to the west.
May 18, 2013 – CHILE – Chilean Navy discovers more than 600 dead animals in Punta de Choros, a small fishing town north of La Serena.
The bodies of sea lions, cormorants and penguins littered a seven mile stretch of beach in Punta de Choros, northern Chile on Sunday. The crime scene is in close proximity to the Humboldt Penguin Nature Reserve.
Two days prior the Movement in Defense of the Environment (MODEMA) reported a band of ten fishing boats off the coastline of Punta de Choros. MODEMA and other environmental groups accused the boats of blast fishing — using explosives to catch mass quantities of fish.
Sernapesca, Chile’s National Fishing Service, investigated the scene and determined that all the animals were killed by the same incident. Autopsies report animales with fractured skulls, missing rib cages and multiple abrasions.
Local authorities promptly called in the Investigative Police’s (PDI) Environmental Crime Brigade for further investigation. Microbiological and chemical analysis tests are currently being run to determine if blast fishing is the cause of death.
In Chile, blast fishing is illegal. Companies caught fishing in this manner face prison time and fines. The monetary amount depends on the damage to the ecosystem. However, causing the death of penguins during commercial activities is a jailable offense. Officials from Sernapesca told The Santiago Times that the combined offenses amount to a “serious crime.”
“This situation is quite complicated because of the crime scene’s location near the penguin reserve,” Cristián Felmer, an environmental expert, stated to the press. “This is one of the most important environmental incidents we’ve had in recent memory.”
This isn’t the first environmental calamity at Punta de Choros. In April of last year, 350 Guayano cormorants washed up on the beach. The next month, Sernapesca reported the deaths of more than 80 sea lions.
In light of the most recent crime, the international marine conservation group Oceana is pushing to have Punta de Choros made a Marine and Coastal Protected Area (AMCP). The proposal would limit human activity along the more than 175-mile coastline to eco-friendly tourism.
“While there are two marine reserves in the area, this ecosystem is much larger and has little protection from threats such as those that apparently killed all these birds,” Alex Muñoz, executive director of Oceana, told press.
Oceana filed a joint proposal with scientists from Universidad Católica and the Center for Advanced Studies in Dry Areas (CEAZA) to make Punta de Choros a AMCP in 2010. The proposal came amid plans to build a thermoelectric power plant in the area. The highly controversial plan was scrapped after generating a wave of protests.
Punta de Choros is a small fishing village of 320 people. It is home to the largest population of Humboldt penguins in the world. The site attracts thousands of tourists annually.
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.
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.
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.
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.
Wednesday, January 30, 2013 at 16:15 in the afternoon at epicenter
Coordinate:
28° 10.104, 70° 48.228
Depth:
47.50 km (29.52 miles)
Hypocentrum:
Shallow depth
Class:
Strong
Region:
South America
Country:
Chile
Location:
45.03 km (27.98 miles) E of Vallenar, Atacama, Chile
Source:
USGS
Generated Tsunami:
Not or no data
Damage:
Not or no data
The potential impact of the earthquake
Drivers have trouble steering. Houses that are not bolted down might shift on their foundations. Tall structures such as towers and chimneys might twist and fall. Well-built buildings suffer slight damage. Poorly built structures suffer severe damage. Tree branches break. Hillsides might crack if the ground is wet. Water levels in wells might change.
A woman takes a picture with her mobile phone of the Copahue volcano spewing ash on Dec. 22, in Caviahue, Neuquen province, Argentina. Antonio Huglich / AFP – Getty Images
Chile issued a top-level red alert Sunday for its Copahue volcano, in the south on the Andean border with Argentina, as it rumbled to register a greater potential threat.
The National Emergency Office issued a red alert but did not order evacuations as no towns are in the current risk area.
“The intensity of seismic signals suggests the eruption in progress is on the smaller side (but) we are not ruling out the possibility that the activity could turn into a larger-scale eruption,” the Geology and Mining Service said in a statement.
While the 2,965-meter (9,700 foot) volcano straddles the two countries’ border, its crater, where most of the activity was under way, leans toward the Argentine side, experts told AFP.
And population in the area is sparse: about 500 people live in Copahue, a tourist town famous for its spa waters, about 900 in the town of Caviahue and an estimated 800 more in local indigenous Mapuche communities.
The June 2011 eruption of Chile’s Puyehue volcano interfered with air travel in much of the southern cone of South America and as far away as Australia.
