Scientists will convene in San Diego to present the latest seismological research at the annual conference of the Seismological Society of America (SSA), April 17-19. This year’s meeting is expected to draw a record number of registrants, with more than 630 scientists in attendance, and will feature 292 oral presentations and 239 poster presentations.

“For over 100 years the Annual Meeting of SSA has been the forum of excellence for presenting and discussing exciting new developments in seismology research and operations in the U.S. and globally,” said Christa von Hillebrandt-Andrade, president of SSA, which is a scientific society devoted to the advancement of earthquake science. von Hillebrandt-Andrade is manager of the NOAA National Weather Service Caribbean Tsunami Warning Program in Puerto Rico.

A special public town hall meeting is scheduled for the evening of April 17, featuring talks by experts on the seismic hazard to San Diego from future earthquakes and tsunamis.

“We are extremely excited by the range, depth, and quality of science to be presented at this meeting” said David Oglesby, associate professor of earth sciences at the University of California, Riverside. “The meeting will cover all aspects of seismology and earthquake science, from geology to numerical models, and from seismograms to tsunamis.

“Our location near the US-Mexican border also help to illuminate the exciting opportunities in international scientific collaborations,” said Oglesby, who is a co-organizer of the conference program along with Raul Castro, a seismologist at the Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Baja California.

The presentations by the international gathering of seismologists will focus on a broad range of topics, covering the Earth’s surface to its center. Some highlights that focus more closely on the San Diego area include:

Downtown San Diego:
The city of San Diego sits atop a fault system that poses considerable seismic hazard to the millions of the region’s residents. In an evaluation by Ivan Wong and colleagues from the URS Corporation, an international engineering consulting firm, the potential hazard from both strong ground shaking and surface faulting was quantified in the downtown area.

Several rupture scenarios of the Rose Canyon fault system were considered including rupture of the associated San Diego fault that traverses downtown San Diego.

The surface faulting hazard for locations along the San Diego fault is estimated to be low because of its low rate of activity but the ground shaking hazard is probably high throughout much of San Diego because of the distributed nature of the Rose Canyon fault system.

The behavior of the Rose Canyon fault system as it traverses San Diego is poorly understood. It is unclear what the role of individual faults in the fault system are in the vicinity of San Diego Bay and the downtown area in a large magnitude 7+ earthquake and how often such events may occur.

“It is clear however that the threat to the city from a future large earthquake is considerable and that research is needed to define what that level of hazard is,” said Ivan Wong, principal seismologist and vice president of URS Corporation.

San Jacinto Fault Zone:
Geophysicist Tom Rockwell, and colleagues from San Diego State University will describe the latest research findings on the San Jacinto Fault (SJF) Zone, which is a seismically active, major component of the overall southern San Andreas Fault system, and of particular importance to the San Diego region. They have mapped evidence of past ruptures consistent with very large earthquakes along the Clark Fault, an individual strand associated with the SJF.

Tom Rockwell and other presenters will discuss their work at a news briefing on April 19, beginning at 12:10 p.m. (local time) in the Terrace Salon 2 room of the Town and Country Resort and Convention Hotel.

Offshore faults:
A new map of active faults off the coast of southern California could clarify some of the earthquake hazard for the region, say Jaime Conrad of the U.S. Geological Survey and colleagues. Although this area is crisscrossed by faults, the seismic hazard posed by their activity isn’t well understood, partly because it’s unclear how much the faults slip and how they interact.

The new map covers a series of faults in the near-shore portion of the region known as the Inner Continental Borderland, located between the coast and the San Clemente fault, about 35-40 miles offshore.

The crumpled and uplifted seafloor from Santa Monica Bay to the Mexican border includes several high-angled and north-south trending faults. Using high-resolution seismic reflection data from a number of sources, including multiple sources of sonar beamed from research ships and unmanned underwater vehicles, the researchers were able to revise the current map in some surprising ways.

The data show linkages between faults that were not known previously, for example, and in some cases show a fault slip rate of 1-2 millimeters per year.

Steam, smoke and hot fragments of rock began to be ejected from Popocatepetl this past weekend.

The volcano is located about 50 miles southeast of Mexico’s capital, Mexico City. The metropolitan area of Mexico City is home to approximately 21 million people.

According to Reuters, Mexico’s National Center for Disaster Prevention this week raised the alert level to three on a scale from one to seven, with seven being the greatest threat.

If eruptions intensify, evacuations of nearby villages may be necessary.

The volcano has had a long history of frequent minor to moderate eruptions.

In 2000, thousands of residents surrounding the nearly 18,000-foot mountain were forced to evacuate. Popocatepetl is North America’s second highest volcano.

Eruptions have occurred in November and June of 2011.

According to VolcanoDiscovery.com, Popocatepetl was dormant during the 1950s, 60s, 70s and 80s.

This is a very active volcanic region of the globe and is known as the Trans-Mexican Volcanic Belt.

Mexico authorities were recommending limiting access to the area, including air travel due to the frequency of the volcanic activity of late.

Ash from volcanoes can be carried into the intake of engines, leading to failure.

During a major eruption, smoke and ash can be carried for hundreds and thousands of miles downwind, depending on weather conditions. Such was the case with Eyjafjallajokull in Iceland during 2010.

Accord to Smithsonian, the last major eruption of Popocatepetl, which including a pyroclastic flow, occurred around 800 AD.

A pyroclastic flow is a combination of lethal hot gas and ash, similar to what happened in Pompeii, Italy.

Popocatepetl is the Aztec word for smoking mountain.

Surface winds in the vicinity of the volcano during April 19, 2012, were generally from the west and northwest, carrying smoke and ash away from the Mexico capital.

The town of Puebla, located southeast of Popocatepetl was reporting volcanic ash in the vicinity for a few hours during April 18.

This story was first published on Monday, April 16, 2012 and has been updated.

Severe outbreaks of new, invasive pests triggered by rising temperatures could threaten Southeast Asia’s multi-billion dollar cassava industry, as well as the livelihoods of the hundreds of thousands of small farmers that rely on the crop for income, according to research from the International Center for Tropical Agriculture (CIAT).

“Warmer conditions and longer dry seasons linked to climate change could prove to be the perfect catalyst for outbreaks of pests and diseases. They are already formidable enemies affecting food crops,” said Pramod K. Aggarwal, regional program leader for Asia at the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).

Around five million small producers across Southeast Asia supply cassava to domestic and foreign processing industries, which convert the roots to animal feed and biofuels and also extract starch for use in a wide variety of food and other products. Thailand’s cassava industry accounts for more than 60 percent of global exports. It is one of the world’s biggest producers of tapioca starch, made from the cassava root. In 2011, Thai farmers exported 2.8 billion metric tons of tapioca starch worth almost 48 billion Thai Baht, according to the Thai Tapioca Starch Association.

For cassava in Southeast Asia, mealybugs and whiteflies are already endemic in the region. But new threats, such as the tiny green mite (Mononychellus mcgregori), are already emerging, says the research, published recently in the scientific journal Tropical Plant Biology.

“The cassava pest situation in Asia is pretty serious as it is,” said Tony Bellotti, a cassava entomologist at CIAT. “But according to our studies, rising temperatures could make things a whole lot worse.”

The research was discussed at “Climate Smart Agriculture in Asia: Research and Development Priorities,” a conference convened in Bangkok this week by the Asia-Pacific Association of Agricultural Research Institutions (APAARI), the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), the World Meteorological Organization (WMO) and the United Nations Development Programme (UNDP).

“One outbreak of an invasive species is bad enough, but our results show that climate change could trigger multiple, combined outbreaks across Southeast Asia, Southern China and the cassava-growing areas of Southern India,” added Belloti. “It’s a serious threat to the hundreds of thousands of smallholder farmers for whom cassava is a lifeline, and their main source of income.”

The green mite was first sighted feeding on cassava in Vietnam in 2009, with further reports from Southern China and additional unconfirmed sightings in Cambodia in 2011. Originally from South America, the tiny mites feed on the leaves of cassava plants, causing them to wither and die. It is closely related to the green mite species Mononychellus tanajoa, which has caused extensive damage to cassava in Africa and South America.

An invasive species-one whose movement is aided by the boom in global travel and trade, and which has no natural enemies in Asia-green mite populations could explode if left unchecked.

The report calls for a range of responses to minimize the risk of outbreaks, and to limit damage where outbreaks occur, under the broad banner of Integrated Pest Management. This includes renewed scientific focus on breeding cassava plants with increased resistance to the pests, minimal use of pesticides to avoid killing any possible natural enemies, as well as the identification, rearing and introduction of so-called “biological control agents”-predator and parasite species that hunt down and kill the pests.

In 2009, Thailand showed how a sudden, severe cassava mealybug outbreak could be swiftly brought under control through the use of the parasitic wasp Anagyrus lopezi, which was released into Thai cassava fields in 2010.

“These pest outbreaks need to be continually monitored,” Bellotti said. “Our research shows that there are specific niches that these exotic species can exploit, not just in Asia, but in Africa and the Americas too.”

Scientists emphasize the importance of taming these threats to cassava because the crop is one of the few that can prosper as the climate changes. Previous CIAT research identified cassava as a “Rambo root,” exceptionally tolerant of higher temperatures and droughts. But while the plant can survive the changing temperatures, in order to fully realize its potential to thrive in the face of climate change, it needs assistance in overcoming the crop pests that also come with modified climates.

The Climate Smart Agriculture conference in Bangkok featured leading agriculture, climate and development experts, as well as government representatives from 14 countries in South and Southeast Asia, who brought similar experiences of how agriculture has changed, discussed the most up-to-date research on the impacts of climate change on food security, and identified the priorities to make agriculture “climate-smart.”

These regions are home to more than 30 percent of the world’s population, but half of the world’s poor and malnourished. Agriculture is the backbone of most economies in the region, with nearly 50 percent of the population dependent on the sector for food and livelihoods. Agriculture, along with forestry and land use change, also account for almost one third of greenhouse gas emissions globally, and some of the most innovative approaches to reducing these emissions have been developed in Southeast Asia, one of the leading exporters of rice and cassava to the rest of the world.

In Vietnam, some farmers are switching from rice to shrimp farming to respond to increased salinity and other changes in water resources. Scientists are also working with farmers to disseminate varieties in Mekong Delta countries that can tolerate a larger amount of saltwater flooding, more acidic water and soil, elevated levels of pollution, and new strains of pests and diseases-all while decreasing the crop’s water usage and emissions footprint.

“Last year’s record flooding in Thailand and Southeast Asia was preceded by a record drought in 2010. These and many other extreme weather events have hammered global food prices,” said Bruce Campbell, program director at CCAFS. “With climate change in South and Southeast Asia expected to reduce agriculture productivity by as much as 50 percent in the next three decades, agriculture must become more productive, more resilient and more climate-friendly. Agriculture needs to shift from being climate dependent to being climate-smart.”

The research was published in Tropical Plant Biology, vol 4, numbers 3-4 Dec 2011.