The Bulgarian government has issued a permit to allow an archaeological expedition in the southwestern Black Sea. The oceanographic expedition will take place from September 10 until October 14 and will be conducted by the Greek research ship 'Aegaeo.'
Research ship Aegaeo [Credit: Matthew Grund/ Woods Hole Oceanographic Institution]
The research ship will map the seabed in the southwestern Black Sea, which is under Bulgarian jurisdiction, in order to identify underwater archaeological sites, noted an official government statement issued in Sofia, Bulgaria.
Furthermore, the research team will collect and analyze seabed samples in order to have more detailed information about environmental changes. The Centre for Maritime Archaeology at the University of Southampton and the UK-based Expedition & Education Foundation have agreed to fully fund the expedition and scientific research on the findings.
The Greek research ship, operated by the Hellenic Centre for Marine Research, is a multipurpose vessel that has already carried out several expeditions in offshore and deep sea locations. It has played a major part in acoustic and oceanographic surveys, environmental sampling, and geological and hydrographic surveying.
The July average temperature across global land and ocean surfaces was 1.46°F (0.81°C) above the 20th century average. As July is climatologically the warmest month for the year, this was also the all-time highest monthly temperature in the 1880-2015 record, at 61.86°F (16.61°C), surpassing the previous record set in 1998 by 0.14°F (0.08°C).
July 2015 Blended Land and Sea Surface [Credit: NOAA]
Separately, the July globally-averaged land surface temperature was 1.73°F (0.96°C) above the 20th century average. This was the sixth highest for July in the 1880-2015 record.
The July globally-averaged sea surface temperature was 1.35°F (0.75°C) above the 20th century average. This was the highest temperature for any month in the 1880-2015 record, surpassing the previous record set in July 2014 by 0.13°F (0.07°C). The global value was driven by record warmth across large expanses of the Pacific and Indian Oceans.
The average Arctic sea ice extent for July was 350,000 square miles (9.5 percent) below the 1981-2010 average. This was the eighth smallest July extent since records began in 1979 and largest since 2009, according to analysis by the National Snow and Ice Data Center using data from NOAA and NASA.
Antarctic sea ice during July was 240,000 square miles (3.8 percent) above the 1981-2010 average. This was the fourth largest July Antarctic sea ice extent on record and 140,000 square miles smaller than the record-large July extent of 2014.
Temperature Percentiles July 2015 Blended Land & Sea Surface Temperature Anomalies in °C [Credit: NOAA]
Global highlights: Year-to-date (January-July 2015)
The year-to-date temperature combined across global land and ocean surfaces was 1.53°F (0.85°C) above the 20th century average. This was the highest for January-July in the 1880-2015 record, surpassing the previous record set in 2010 by 0.16°F (0.09°C).
The year-to-date globally-averaged land surface temperature was 2.41°F (1.34°C) above the 20th century average. This was the highest for January-July in the 1880-2015 record, surpassing the previous record of 2007 by 0.27°F (0.15°C).
The year-to-date globally-averaged sea surface temperature was 1.21°F (0.67°C) above the 20th century average. This was also the highest for January-July in the 1880-2015 record, surpassing the previous record of 2010 by 0.11°F (0.06°C). Every major ocean basin observed record warmth in some areas.
Much of the European continent has been affected by severe drought in June and July 2015, one of the worst since the drought and heat wave of summer of 2003, according to the latest report by the JRC's European Drought Observatory (EDO). The drought, which particularly affects France, Benelux, Germany, Hungary, the Czech Republic, northern Italy and northern Spain, is caused by a combination of prolonged rain shortages and exceptionally high temperatures.
Satellite imagery and modelling revealed that the drought, caused by prolonged rainfall shortage since April, had already affected soil moisture content and vegetation conditions in June. Furthermore, the areas with the largest rainfall deficits also recorded exceptionally high maximum daily temperatures: in some cases these reached record values.
Another characteristic of this period was the persistence of the thermal anomalies: in the entire Mediterranean region, and particularly in Spain, the heat wave was even longer than that of 2003, with maximum daily temperatures consistently above 30°C for durations of 30 to 35 days (even more than 40 days in Spain).
While sectors such as tourism, viticulture and solar energy benefited from the unusual drought conditions, many environmental and production sectors suffered due to water restrictions, agricultural losses, disruptions to inland water transport, increased wildfires, and threats to forestry, energy production, and human health.
Rainfall is urgently needed in the coming months to offset the negative impacts of the 2015 drought situation. The current seasonal weather forecast envisages more abundant rains for the Mediterranean region in September, but no effective improvement is yet foreseen for parts of western, central and eastern Europe.
Management of boreal forests needs greater attention from international policy, argued forestry experts from the International Institute for Applied Systems Analysis (IIASA), Natural Resources Canada, and the University of Helsinki in Finland in a new article published this week in the journal Science. The article, which reviews recent research in the field, is part of a special issue on forests released in advance of the World Forestry Congress in September.
Taiga Landscape in Quebec, Canada, dominated by Black Spruce Picea mariana [Credit: WikiCommons]
"Boreal forests have the potential to hit a tipping point this century," says IIASA Ecosystems Services and Management Program researcher Anatoly Shvidenko. "It is urgent that we place more focus on climate mitigation and adaptation with respect to these forests, and also take a more integrated and balanced view of forests around the world."
Boreal forests, which sprawl across the northernmost regions of Canada, Russia, Alaska, and Scandinavia, make up about 30% of total forest area on the planet. They play a vital role in Earth's climate system by sequestering carbon dioxide from the atmosphere. They are home to a plethora of plants and animals. And they provide resources including substantial amounts of wood for lumber and biofuel production, as well as economic and resource opportunities for local and indigenous people.
At the same time, boreal forests are one of the ecosystems most affected by climate change, with temperatures in the arctic and boreal domains recently warming at rates as high as 0.5°C per decade, and potential future warming of 6 to 11°C over vast northern regions by 2100, according to the IPCC's most pessimistic scenario, RCP 8.5.
Studies have shown that climate zones in boreal forests are moving northwards ten times faster than the trees' ability to migrate. Warmer and drier conditions and enhanced variability of climate may have already contributed to increased extent of wildfires, and the spread of outbreaks of dangerous insects. Thawing permafrost poses threats to the hydrological system at the continental scale, as well as the potential of releasing huge amounts of CO2 and methane. Locally, increasing non-forestry industrial development, accompanied by air pollution, soil and water contamination, might reinforce the negative impacts of climate change. Overall, these factors mean that huge areas of boreal forest will be at high risk of impoverishment or change to grassland or shrubland.
"These forests evolved under cold conditions, and we do not know enough about the impacts of warming on their resilience and buffering capacity," says Shvidenko.
In the article, the researchers call for governments and societies to place greater focus on the health of boreal forests, meaning the forests' resilience, adaptive capacity, and productivity. Transition to adaptive forest management is an urgent need for securing future sustainable development of boreal forests. They also stress the key role of monitoring and research to continuously assess the state of boreal forests and improve the understanding of feedbacks and interactions in order to decrease the risk of catastrophic tipping points, where the forests switch from being a net sink for CO2 to a major source of increased greenhouse gas emissions.
A pockmarked, icy landscape looms beneath NASA's Cassini spacecraft in new images of Saturn's moon Dione taken during the mission's last close approach to the small, icy world. Two of the new images show the surface of Dione at the best resolution ever.
This view from NASA's Cassini spacecraft looks toward Saturn's icy moon Dione, with giant Saturn and its rings in the background, just prior to the mission's final close approach to the moon on August 17, 2015 [Credit: NASA/JPL-Caltech/Space Science Institute]
Cassini passed 295 miles (474 kilometers) above Dione's surface at 11:33 a.m. PDT (2:33 p.m. EDT) on Aug. 17. This was the fifth close encounter with Dione during Cassini's long tour at Saturn. The mission's closest-ever flyby of Dione was in Dec. 2011, at a distance of 60 miles (100 kilometers).
Dione hangs in front of Saturn and its icy rings in this view, captured during Cassini's final close flyby of the icy moon [Credit: NASA/JPL-Caltech/Space Science Institute]
"I am moved, as I know everyone else is, looking at these exquisite images of Dione's surface and crescent, and knowing that they are the last we will see of this far-off world for a very long time to come," said Carolyn Porco, Cassini imaging team lead at the Space Science Institute, Boulder, Colorado. "Right down to the last, Cassini has faithfully delivered another extraordinary set of riches. How lucky we have been."
Saturn's moon Dione hangs in front of Saturn's rings in this view taken by NASA's Cassini spacecraft during the inbound leg of its last close flyby of the icy moon [Credit: NASA/JPL-Caltech/Space Science Institute]
The main scientific focus of this flyby was gravity science, not imaging. This made capturing the images tricky, as Cassini's camera was not controlling where the spacecraft pointed.
NASA's Cassini spacecraft captured this parting view showing the rough and icy crescent of Saturn's moon Dione following the spacecraft's last close flyby of the moon on Aug. 17, 2015 [Credit: NASA/JPL-Caltech/Space Science Institute]
"We had just enough time to snap a few images, giving us nice, high resolution looks at the surface," said Tilmann Denk, a Cassini participating scientist at Freie University in Berlin. "We were able to make use of reflected sunlight from Saturn as an additional light source, which revealed details in the shadows of some of the images."
NASA's Cassini spacecraft gazes out upon a rolling, cratered landscape in this oblique view of Saturn's moon Dione [Credit: NASA/JPL-Caltech/Space Science Institute]
Cassini scientists will study data from the gravity science experiment and magnetosphere and plasma science instruments over the next few months as they look for clues about Dione's interior structure and processes affecting its surface.
This view from NASA's Cassini spacecraft shows terrain on Saturn's moon Dione that is entirely lit by reflected light from Saturn, called Saturnshine [Credit: NASA/JPL-Caltech/Space Science Institute]
Only a handful of close flybys of Saturn's large, icy moons remain for Cassini. The spacecraft is scheduled to make three approaches to the geologically active moon Enceladus on Oct. 14 and 28, and Dec. 19. During the Oct. 28 flyby, the spacecraft will come dizzyingly close to Enceladus, passing a mere 30 miles (49 kilometers) from the surface. Cassini will make its deepest-ever dive through the moon's plume of icy spray at this time, collecting valuable data about what's going on beneath the surface. The December Enceladus encounter will be Cassini's final close pass by that moon, at an altitude of 3,106 miles (4,999 kilometers).
This view of Dione from Cassini includes the mission's highest-resolution view of the icy moon's surface as an inset at center left [Credit: NASA/JPL-Caltech/Space Science Institute]
After December, and through the mission's conclusion in late 2017, there are a handful of distant flybys planned for Saturn's large, icy moons at ranges of less than about 30,000 miles (50,000 kilometers). Cassini will, however, make nearly two dozen passes by a menagerie of Saturn's small, irregularly shaped moons—including Daphnis, Telesto, Epimetheus and Aegaeon—at similar distances during this time. These passes will provide some of Cassini's best-ever views of the little moons.
A region on Dione where features in shadow are illuminated by reflected light from Saturn. Inset above center is one of Cassini's highest-resolution views of Dione's surface [Credit: NASA/JPL-Caltech/Space Science Institute]
During the mission's final year—called its Grand Finale—Cassini will repeatedly dive through the space between Saturn and its rings.
Extreme thermal stresses experienced by a comet as it orbits around the Sun could explain the extensive fracturing thought to drive its long-term surface erosion, say Rosetta scientists analysing high-resolution images of Comet 67P/Churyumov-Gerasimenko's surface.
Variety of fracture networks on comet 67P/C-G [Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
The study, which is published online in the journal Geophysical Research Letters, is based on images taken between 6 August 2014 – when Rosetta first arrived at the comet – and 1 March 2015, and includes detailed images acquired from between just 8 and 18 km from the comet's surface.
Lead author M. Ramy El-Maarry and his team identified three distinct settings in which the fractures occur: networks of long narrow fractures, fractures on cliffs and fractured boulders. In addition, several unique features were identified: the parallel fractures running across Hathor's 900 m-high cliffs, an isolated 500 metre-long crevice in the Anuket region of the comet's neck, and a 200 m-long complex crack system in Aker on the large lobe.
"The fractures show a variety of morphologies and occur all over the surface and at all scales: they are found in the towering 900 m-high cliffs of Hathor right down to the surfaces of boulders a few metres across," describes El-Maarry from the University of Bern.
Fractures found on cliffs on comet 67P/C-G [Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
The most prevalent setting appears to be networks of narrow fractures that extend for a few metres to 250 m in length, typically on relatively flat surfaces. Interestingly, in some locations, the fractures appear to cross cut each other in polygonal patterns at angles of 90° – on Earth and Mars this is often an indicator of ice that has contracted below the surface.
Another family of cross-cutting fractures is observed on cliff faces, such as in the Seth region on the comet's large lobe, with debris deposits littering their bases. Fractured cliff faces were also observed at Abydos, the final landing site of Philae on the small lobe, as recorded in images from the lander. The fact that the fractures cut across each other in different directions suggests that the stress direction changes over time.
At the smallest scale, fractures are observed on boulders (in this study, boulders 20-60 m wide were analysed). In some cases it is clear that the fractures run through the boulders, pervasively fracturing them, while other fractures appear confined to the boulder's surfaces. Taken together, the fracturing points to an erosional sequence leading to the boulders' eventual fragmentation.
Fractured boulders on comet 67P/C-G [Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Scientists think that the majority of these fracture patterns are most likely linked to the thermal history of the comet and result from stresses that stretch the comet's surface apart. On Earth and Mars at least, these 'tensile' fractures can develop through several common processes: loss of volatile materials, thermal contraction or contraction and expansion cycles, and tectonic processes.
In addition to throwing off volatile materials as they near the Sun, comets are known to undergo high fluctuations in surface and subsurface temperature on daily and seasonal timeframes. This continuous thermal 'shock' leads to weakening or "fatigue" of the surface both on the short term due to daily heating cycles, and on the long term as the seasons change along the comet's 6.5 year orbit around the Sun.
"But the presence of fractures in different settings, in addition to the isolated fractures in Anuket and Aker, suggests that other mechanisms may also be at work," comments Ramy. "For example, perhaps mechanical forces related to the comet's rotation or orbit around the Sun are responsible for the crack in Anuket, while the fractured cliffs of Hathor could have resulted from the comet's formation, perhaps when two smaller cometisimals collided."
A 200-m complex fracture system in the Aker region, on the comet large lobe [Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Regardless of the origin of individual fracture systems, it is clear that fracturing plays an important role in the evolution of the comet's surface.
Fractures observed in cliffs, with debris observed at their bases, imply that this phenomenon represents the first stage in the overall 'mass-wasting' of the comet: the cliff top is weakened and a landslide-type event ensues.
But, over long periods this process would act to erode the surface and flatten the landscape. The fact that there are many rough terrains on the comet suggests that it has either not gone through very many erosional cycles or other processes are acting against this to roughen the surface, such as explosive jet activity.
"Monitoring for changes in these fracture systems after the current perihelion phase, and running models to simulate the evolution of the comet over time, will enable us to test our various hypotheses for fracture formation," adds Ramy.
Two 3,900-year-old female skeletons from the Bronze Age have been unearthed at Oylum Mound in the southeastern Turkish province of Kilis.
Archaeologists excavate one of two 3,900-year-old female skeletons found at the Oylum Mound [Credit: AA]
Oylum is located three kilometers away from the Syrian border and is one of the largest mounds in the southeastern Anatolian region in terms of its size. Excavations have been carried out by a team from the Cumhuriyet University Archaeology Department. Sixty people, 25 of whom are academics, are working at the site.
Excavations head Associated Professor Atilla Engin said they were almost done with the excavations this year. He said they compiled important data during the work, and added, “We worked particularly in the layers of the Mid Bronze Age. We can say that the big monumental structure that was unearthed in previous years was a palace.”
Engin said the structure had at least three floors, and continued: “The most important part of the palace is the area where the king lived with his family and was called seraglio. The structure was exposed to a severe fire. We think that the fire was caused by an attack. We unearthed some parts of the palace and found 3,900-year-old female skeletons. We think they burned to death in the palace.”
Engin said a large portion of the palace was still underground.
He said they would begin a new project to protect the palace, and Oylum Mound could become an open-air museum in future.
“We have found housings and narrow streets here. The dead people were buried inside the houses,” he said.
Archaeologists have found the main trophy rack of sacrificed human skulls at Mexico City's Templo Mayor Aztec ruin site, scientists said Thursday.
Skulls are partially unearthed at the Templo Mayor Aztec ruin site in Mexico City [Credit: PAU-INAH]
Racks known as "tzompantli" were where the Aztecs displayed the severed heads of sacrifice victims on wooden poles pushed through the sides of the skull. The poles were suspended horizontally on vertical posts.
Eduardo Matos, an archaeologist at the National Institute of Anthropology and History, suggested the skull rack in Mexico City "was a show of might" by the Aztecs. Friends and even enemies were invited into the city, precisely to be cowed by the grisly display of heads in various stages of decomposition.
Paintings and written descriptions from the early colonial period showed descriptions of such racks. But institute archaeologists said the newest discovery was different.
Part of the platform where the heads were displayed was made of rows of skulls mortared together roughly in a circle, around a seemingly empty space in the middle. All the skulls were arranged to look inward toward the center of the circle, but experts don't know what was at the center.
INAH archaeologists believe they have found the site's main trophy rack of sacrificed human skulls, known as "tzompantli" [Credit: PAU-INAH]
Archaeologist Raul Barrera said that "there are 35 skulls that we can see, but there are many more" in underlying layers. "As we continue to dig the number is going to rise a lot."
Barrera noted that one Spanish writer soon after the conquest described mortared-together skulls, but none had been found before.
University of Florida archaeologist Susan Gillespie, who was not involved in the project, wrote that "I do not personally know of other instances of literal skulls becoming architectural material to be mortared together to make a structure."
The find was made between February and June on the western side of what was once the Templo Mayor complex.
Circular element made from skulls [Credit: PAU-INAH]
The platform was partly excavated under the floor of a three-story colonial era house. Because the house was historically valuable, archaeologists often worked in narrow excavation wells six feet (two meters) under the floor level suspended on their stomachs on a wooden platform.
Periodic excavations carried out since 1914 suggested a ceremonial site was located near the site. Barrera said the location fit very well with the first Spanish descriptions of the temple complex.
Gillespie said archaeologists have found other tzompantli, which she said might be better translated as "head rack" instead of "skull rack" because the heads were put up for display while still fresh.
But experts had long been searching for the main one.
"They've been looking for the big one for some time, and this one does seem much bigger than the already excavated one," Gillespie wrote. "This find both confirms long-held suspicions about the sacrificial landscape of the ceremonial precinct, that there must have been a much bigger tzompantli to curate the many heads of sacrificial victims" as a kind of public record or accounting of sacrifices.
Unmanned aerial vehicles (UAV) have been gaining attention in the news for the last few years, but archaeologists like Saint Louis University history professor Thomas Finan, Ph.D., have always appreciated what aerial photography could accomplish.
Unmanned aerial vehicles served as important tools in research at the Lough Key archaeological site [Credit: Saint Louis University]
Finan says UAV technology, along with high speed computer applications and mapping software, and sensors that can collect multi-spectral image are changing archaeology, adding that unmanned aerial survey is the next great jump in archaeological technology.
For nearly 20 years, Finan has spent summer breaks on archaeological digs, often taking SLU students to areas such as North Roscommon in Ireland in search of ancient sites, relics and a deeper glimpse of history.
Finan has now partnered with Paul Naessens, director of Western Aerial Survey, and a field archaeologist he has worked with for two years in North Roscommon, to further their exploration through the use of UAVs.
"Paul is not only a great archaeologist," said Finan. "He is fully licensed by the Irish Aviation Authority to carry out these surveys and broaden our knowledge of the area."
Finan has been working in north County Roscommon for the last two decades, conducting archaeological explorations at a number of sites, including the ecclesiastical complex at Kilteasheen, the Rock of Lough Key, the MacDermot moated site stronghold near the Rock, six ringforts (smaller agricultural settlements) and the Kilbrian ecclesiastical site. He says the landscape is breathtaking, but the archaeology is even more incredible.
"In 2013-14, we identified what we believe to be a major medieval Gaelic settlement in proximity to the Rock of Lough Key, a stunning island fortification," Finan said. "This year, we focused our attention on some lesser known sites in the area, including a ringfort that shows great promise for medieval settlement and what appears to be a major settlement in association with the parish church at Kilbrian."
The survey, conducted as part of an ongoing field survey of north Roscommon, brings together the latest in archaeological technology to enhance the understanding of sites that had been identified before.
"Most of these sites are found in the inventory of the National Monuments Service, but are often given cursory classification distinctions," Finan added. "My interest is piecing together various medieval settlements (high status lordly sites, ecclesiastical sites, lower status agricultural sites) to explain social dynamics and the events of the thirteenth century in particular."
Finan's team uses traditional tools such as gradiometry, electrical resistivity and topographical surveys to identify features in the landscape. The aerial survey adds a completely new element to the study.
"We have collected an unprecedented amount of digital data," Finan said. "The 3D landscape data allows us to see minute changes in the topography that can be defined as structures and human occupation. The digital data collected with the geophysics is then wrapped around that 3D data to give us an amazing understanding of what is there without sinking a spade."
Finan says managing this data has been a challenge. The amount of data collected in aerial survey fills hard drives quickly, and dealing with archiving and storage is a major pre-occupation for the team.
"We build a great deal of redundancy into the project, but in reality the management of the data revolves around developing tools that can both archive and present the data in new ways. This is really where the cutting edge of digital archaeology is right now. We have tons of digital data, but what do we do with it? From our perspective, we have chosen to make the data freely available to anyone who wants to use it for scholarly purposes with proper attribution using an open-data policy. Our next step is to integrate that database with other archaeological information that has been collected over the years from excavations, archives and even aerial photos from a hundred years ago."
While the project is ongoing, Finan is content with saying that the process of data collection is reaching a significant milestone after only three years.
"When combined with the rich collection of historical sources that we have for north Roscommon in the thirteenth century, this research has huge potential to change the way we understand that century. But what is more important to me is that the local population in north Roscommon appreciates this research and has been so helpful to us all these years. Farmers have told us about sites not recorded, have given us access to their lands, and have been thrilled to see students from America working in their area. It continues to be a great experience for all involved."
Portuguese researchers suspect that a dozen skeletons found in an ancient garbage dump were Jewish victims of the Inquisition more than 400 years ago.
Skeleton from the excavation of the jail cleaning yard associated with the Inquisition Court at Évora, Portugal [Credit: Bruno Magalhães]
The excavation team found the remains at what was called the Jail Cleaning Yard of the Inquisition Court in Evora, 135 kilometres east of the Portuguese capital, Lisbon. The dump was in use roughly between 1568 and 1634.
The three male and nine female bodies “were discarded into the dump like household garbage,” with no funeral structures nor grave goods, and the skeletons were lying skewed on the ground, the researchers said in the September edition of the Journal of Anthropological Archaeology, provided to The Associated Press on Wednesday.
A view of the jail cleaning yard at the old Inquisition Court at Évora during excavation. Archaeologists excavated about one-eighth of the area and found bones from more than two dozen individuals jailed during the Portuguese Inquisition [Credit: Bruno Magalhães]
The Portuguese Inquisition was established in 1536. Its most common accusation was maintaining outlawed Jewish practices in secret. Hundreds of Jews were burned at the stake, and living conditions in Inquisition jails often caused prisoners’ deaths. A proper burial was denied to Jews.
The researchers said it was impossible to know for certain if the skeletons were of Jews.
The excavations were carried out in 2007 and 2008 during the renovation of the former Inquisition court building. Only 12 per cent of the yard was excavated, researchers from the Portuguese universities of Evora and Coimbra said.
