Thursday, December 21, 2006


Scripps News at 2006 AGU Fall Meeting

Scripps Institution of Oceanography / University of California, San Diego

First Results from a Revolutionary Observation Campaign


Monday, Dec. 11, 1:40 p.m. · Moscone West Level 2


Tuesday, Dec. 12, 9:45 a.m. Moscone West 3001


Wednesday, Dec. 13, 1:40 p.m. · Moscone West Level 2


Thursday, Dec. 14, 1:40 p.m. · Moscone West Level 1



Ramanathan with AUAVs
In March, Scripps Institution of Oceanography at UC San Diego scientists led by V. Ramanathan deployed a fleet of autonomous unmanned aerial vehicles (AUAVs) over the Indian Ocean in the vicinity of the Maldives, an island chain nation south of India. The miniaturized instruments borne on the aircraft, which flew in stacked formation to provide multiple perspectives on cloud-filled skies, gathered data on albedo, aerosol concentration, solar absorption and other phenomena in a manner never before possible. Four presentations will discuss initial findings and observations from the Maldives AUAV Campaign.

PRESENTATION TITLES: "SIMULTANEOUS MEASUREMENTS OF DIRECT, SEMI-DIRECT AND INDIRECT AEROSOL FORCING WITH STACKED AUTONOMOUS UAVs": A NEW OBSERVING PLATFORM; "DIRECT MEASUREMENTS OF ALBEDO AND SOLAR ABSORPTION OVER THE NORTHERN INDIAN OCEAN WITH A NEW OBSERVING SYSTEM OF STACKED MULTIPLE UAVs"; "CHASING BLACK CARBON USING AUTONOMOUS UNMANNED AERIAL VEHICLES"; "SIMULTANEOUS OBSERVATIONS OF AEROSOLS, CLOUDS, AND RADIOMETRIC FLUXES USING LIGHT-WEIGHT AUTONOMOUS UAVs"

One-Two Punch of El Niño and Hurricane Lurk Behind Damage Found in Coral


Monday, Dec. 11, 5 p.m. · Moscone West Room 3016



coral reef

Photo by Brad Erisman



Not unlike methods for reading tree rings, annual growth bands found in cores extracted from coral reefs can provide unique insight about the health of the reef ecosystem and the environment around it. Jessica Carilli of Scripps Oceanography extracted several coral core samples from a barrier reef off Belize, part of a group that has been declining in health over the past few decades, and is deciphering the information they reveal. A preliminary analysis using x-rays has shown decades of largely undisturbed coral growth with one glaring exception: 1998-1999, when so-called "stress bands" reveal a clear picture of stunted coral growth at that time. Carilli and her advisor, Scripps Professor Richard Norris, hypothesize that the damage is the result of a combination of the high temperatures from the 1998-1999 El Niño event, combined with coastal runoff plumes triggered by 1998's devastating Hurricane Mitch. Norris said the elimination of mangrove forests, which act as coastal buffer zones in the region, is likely accelerating the coral damage caused by runoff. Further investigations will attempt to differentiate between the effects caused by the El Niño and the hurricane-induced runoff.


PRESENTATION TITLE: "WIDESPREAD REDUCTION IN CORAL GROWTH RATES ON THE MESOAMERICAN REEF FOLLOWING THE 1998 EL NINO AND HURRICANE MITCH"

Probing the Inner Workings of a Global Phenomenon at the Cellular Level


Tuesday, Dec. 12, 11:50 a.m. · Moscone West 3016



diatom


Diatoms, the microscopic algae that make up a large component of the world's plankton population, play large roles in the planet's carbon cycling and as a major food source for marine and freshwater microorganisms. Because their cell walls are made of silica, or silicon dioxide, diatoms also are largely responsible for silica formation on a global scale as well as silicon cycling. Mark Hildebrand of Scripps Institution of Oceanography is probing the root of silica cell wall formation in diatoms using a variety of approaches, including molecular, genomic, transgenic and imaging techniques. His investigations of structure formation in a diatom known as Thalassiosira pseudonana have uncovered specific stages, including a "spatial cementing" process that begins with a thin silica outline and subsequent gradual thickening of the cell wall. Hildebrand also uses sophisticated imaging techniques to visualize the silicification process.


PRESENTATION TITLE: "BIOGENIC SILICA STRUCTURE FORMATION IN DIATOMS: CELLULAR COMPONENTS AND CONTROL"

Damage Zones Surrounding Calico Fault Found Wider Than Expected


Tuesday, Dec. 12, 2:10 p.m. · Moscone South Room 300




Earthquakes can trigger other earthquakes on nearby faults through stress interactions, but the mechanics of fault communication is not well understood. This study focuses on the Calico Fault in the Mojave desert near Barstow, Calif., part of the Eastern California Shear Zone (ECSZ), currently the most active seismic region in southern California. To map the shallow and deep fault structure, the scientists set up nearly 100 seismometers along a section of the Calico Fault that exhibited anomalous strain in response to the 1992 Landers (magnitude 7.3) and 1999 Hector Mine (magnitude 7.1) earthquakes. Both planned explosions and natural earthquake activity were recorded during a six-month period. The preliminary results of the seismic experiment show that the damage zone surrounding the fault extends up to a kilometer away from the fault trace, in agreement with previous suggestions based on satellite remote-sensing imaging. These data demonstrate that fault damage zones may be much wider than previously believed. The new observations indicate that a significant portion of the energy released during earthquakes goes into cracking and yielding of rocks around the fault. These findings show that faults may affect rock properties at significant distances from the actual fault slip surfaces, a result likely to have implications for the partitioning of the stress buildup that leads to large earthquakes.


PRESENTATION TITLE: "SEISMIC IMAGING OF THE DAMAGE ZONE AROUND THE CALICO FAULT"

A Desert Is a Sometimes Thing: Drought and Warming Could Increase the Arid Regions of the West by 18 Percent


Wednesday, Dec. 13, 1:40 p.m. · Moscone West Level 2




The areas of the western United States considered desert are constantly in flux as El Niños and other climate cycles leave their mark.

Scripps Oceanography researchers led by hydrologist Hugo Hidalgo have created an aridity index that compares actual and potential rates of evapotranspiration, the total loss of moisture from plants, bodies of water and soil to the atmosphere. Breaking down the West into "energy-limited," semi-arid and arid regions, Hidalgo's team found that a temperature increase of 3 degrees Celsius-a conservative scenario forecast by several climate models-or a 5 percent decrease in precipitation would cause currently arid areas of the West to expand nearly 20 percent and lead to desertification in some places. Hidalgo's forecast sees a corresponding decrease in energy-limited regions, such as the higher elevations of mountains, that experience year-round soil moisture. The analysis highlights the need for further research to help distinguish natural variability from the signals of the current climate change trend.


PRESENTATION TITLE: "DROUGHT - HOW THE WESTERN U.S. IS TRANSFORMED FROM ENERGY-LIMITED TO WATER-LIMITED LANDSCAPES"

Electromagnetic Method Provides Improved Imaging Beneath the Seafloor


Wednesday, Dec. 13, 2:10 p.m. · Moscone South Room 256



Most of the earth's crust is manufactured at mid-ocean ridges that encircle the globe where magma erupts, solidifies and spreads out, covering the planet over millennia.
electromagnetic transmitter

A marine electromagnetic transmitter (above) and an electromagnetic receiver (right) are deployed at sea.

Unfortunately, little is known about the details of this deep-sea volcanic process because the oceans hinder direct observations. Geophysicist Steven Constable is a pioneer in the use of a technique developed at Scripps Institution of Oceanography that uses electromagnetic imaging to probe the seafloor. In this presentation, Constable presents new data on defining the shape and size of magma chambers at a section of the East Pacific Rise.
electromagnetic receiver
Electromagnetic imaging doesn't replace traditional seismic surveying, but instead gives improved detail because it can penetrate through many types of obstructions that block seismic methods. The technique is also being hailed as the most significant new exploration tool for the oil industry in many decades.


PRESENTATION TITLE: "ELECTROMAGNETIC IMAGING OF CRUSTAL MAGMA CHAMBERS"

Beyond Jargon: What Stops Some Scientists from Communicating Their Findings to the Public and How They Could Do Better


Thursday, Dec. 14, 8 a.m. · Moscone West Room 3006



Researchers interested in communicating science to the general public must confront a variety of obstacles to achieve their goal, many of them self-imposed. Scripps Oceanography climate scientist Richard Somerville notes that barriers to public understanding of science arise when researchers perceive outreach as being detrimental to their careers or when they despair that their target audience is too apathetic or uneducated to appreciate their messages. Somerville, a featured speaker in the union session "Communicating Broadly: Perspectives and Tools for Ocean, Earth, and Atmospheric Scientists I," makes the case that societal concerns about climate change demand effective communication of science. The present day is a time of opportunity, said Somerville, who proposes that universities create incentives for researchers to do more to reach out. He cites the Aldo Leopold Leadership Fellowship as a model program for preparing scientists to bridge the gap between science and the public.


PRESENTATION TITLE: "PUNISHMENTS AND PRIZES FOR EXPLAINING GLOBAL WARMING"

New Instruments Probe Hazards off Santa Barbara


Thursday, Dec. 14, 1:40 p.m · Moscone West Level 1



Preliminary surveys of the seafloor structure off Santa Barbara have revealed evidence of a geologically active region with a history of massive landslides, earthquakes and tsunamis. An area called the Goleta slide shows evidence of slope failure nearly 11 kilometers wide and 14 kilometers long, failing in stages 10-30 thousand years ago. Earthquakes of magnitudes 7.1 and 7.5 in 1812 likely triggered the smaller, adjacent Gaviota slide (1.5 kilometers wide and 2.5 km long), possibly responsible for a reported 1- to 2-meter tsunami. Scientific models estimate that a similar event in the Goleta area carries the potential for a 5-meter-high tsunami at the Santa Barbara shoreline. To better understand these and related geological hazards in the region, Scripps Oceanography and BP America have launched a collaborative study using an array of new and emerging instrumentation that will probe the seafloor and its historical composition like never before.
underwater landslide

A crack is visible from the Gaviota slide (left) towards the Goleta slide (right) near Santa Barbara. Planned research deployments include acoustic geodesy transponders and nodes (yellow cubes and spheres), FOSS cables (red lines) and sediment cores (orange cylinders).

An underwater acoustic geodesy network, which measures sea-floor movements to 5 millimeters between points in the network, has been deployed. A new autonomous underwater vehicle for repeat surveys is in development, along with a novel device called a fiber optic seafloor strainmeter, or FOSS. The FOSS will measure ultra-fine seafloor movements to a precision of 1.5 millimeters and will be buried across a 4-meter-deep seafloor crack that extends between the Gaviota and Goleta slides. The new geodetic instruments will help researchers answer questions such as whether the crack is a benign remnant of previous events or represents evolving seafloor changes that could lead to a new geological failure and subsequent tsunami.

PRESENTATION TITLE: "MONITORING POTENTIAL SLOPE FAILURE IN THE SANTA BARBARA BASIN USING OPTICAL FIBERS"

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Note to broadcast and cable producers: University of California, San Diego provides an on-campus satellite uplink facility for live or pre-recorded television interviews. Please phone or e-mail the media contact listed above to arrange an interview.

Scripps Institution of Oceanography, at University of California, San Diego, is one of the oldest, largest and most important centers for global science research and education in the world. The National Research Council has ranked Scripps first in faculty quality among oceanography programs nationwide Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today in 65 countries. The institution has a staff of about 1,300, and annual expenditures of approximately $155 million from federal, state and private sources. Scripps operates one of the largest U.S. academic fleets with four oceanographic research ships and one research platform for worldwide exploration.


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