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Imaggeo on Mondays

Imaggeo on Mondays: Indonesian mangroves and tsunamis

Imaggeo on Mondays: Indonesian mangroves and tsunamis

Pictured here is a solitary mangrove tree, rooted off the northern coast of the Indonesian island Flores. While this tree has the shallow sandy reef to itself, mangroves are often found clumped together in large forests covering tropical and subtropical coastlines. The propped-up roots of mangrove trees often tangle together, creating a dense natural barrier that can weaken the coastal impact of ocean tides, currents and storms. As a consequence, islands with mangrove forests on their coastlines experience less erosion and less damage from storm surges compared to barer shorelines.

Mangroves are also often said to provide protection against tsunami destruction. Indeed, there have been several cases in which mangroves trees were believed to have curtailed the devastating effect of tsunami waves. Recent research suggests that extensive mangrove forests hundreds of metres wide have been able to reduce tsunami wave heights by 5-30 percent.

Unfortunately, over the past decades, these environmental benefits are now under threat due to deforestation. About half of the global mangrove population (32 million hectares) has been wiped out, often to make way for fish farming operations. In Indonesia, mangrove ecosystem decline has been largely attributed to developing shrimp ponds and logging activities. There are now a number of places where mangrove plantations are supported by local individuals and governments.

Jörn Behrens, a professor of numerical methods in Earth sciences at the University of Hamburg in Germany, captured this shot while on a field trip in Indonesia. He and his colleagues were looking for traces of the powerful 1992 tsunami that struck the coast of the Indonesia island of Flores and other nearby smaller islands.

The tsunami, triggered by a magnitude 7.9 earthquake, sent waves reaching 4 to 27-metres high on the island’s northeastern coast, even destroying a whole village situated on the nearby island Babi. About 2,500 residents and tourists died from the event, with hundreds more injured, and thousands more homeless.

The 1992 Flores tsunami was also one of the first such events documented by an international survey that adhered to internationally accepted post-tsunami assessment standards.  On their field trip Behrens and his colleagues revisited some of sites assessed by the 1992 post-tsunami survey, spoke to eye witnesses, learned about the region’s current mitigation measures, and exchanged latest results from modeling and experimental tsunami research.

While on this field trip, Behrens came across this solitary mangrove, surrounded by what appears to be young mangrove propagules growing out from the water.

By Olivia Trani, EGU Communications Officer

References

Spalding M, McIvor A, Tonneijck FH, Tol S and van Eijk P (2014) Mangroves for coastal defence. Guidelines for coastal managers & policy makers. Wetlands International and The Nature Conservancy.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: Penguins – a biogeochemical link between sea and land

Imaggeo on Mondays: Penguins – a biogeochemical link between sea and land

A couple of Chinstrap penguins (Pygoscelis antarctica) at their nesting site on Deception Island, maritime Antarctica. Sea birds contribute importantly to biogeochemical cycles in coastal ecosystems and on islands. Feeding on the marine food chain and nesting on land, they carry large amounts of marine nutrients into terrestrial ecosystems. This might be of particular importance for the nitrogen (N) cycle of terrestrial ecosystems in the antarctic. In the form of ammonia, marine derived N can travel far inland with the wind, and perhaps represent an important nutrient source for the growth of mosses.

Description by Daniel Wasner, as it first appeared on imaggeo.egu.eu.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: Up close and personal with Svalbard glaciers

Imaggeo on Mondays: Up close and personal with Svalbard glaciers

A University Centre in Svalbard (UNIS) Glaciology student examines the calving front of the Paulabreen glacier [in Spitsbergen, Svalbard], taking advantage of sea ice in the Rindersbukta fjord to safely approach the front. Paulabreen is a surge-type glacier, which means that it periodically switches between long periods of slow, stable flow to short-lived periods of very fast flow during which it advances.

Paulabreen last surged between 2003 and 2006, advancing 1.5km in that period. This rapid advance turned the calving front into a crevassed and jumbled mess. In this photo we see a mix of glacier ice, refrozen water ice and crevasses infilled with basal sediments, resulting in a beautiful and chaotic pattern of contrasting textures, twisted into place by the grinding force of the surge.

Description by Matt Trevers, as it first appeared on imaggeo.egu.eu.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: Simulating a mission on Mars

Imaggeo on Mondays: Simulating a mission on Mars

Establishing a human presence on Mars is increasingly seen by space agencies and private organizations as the horizon frontier in human space exploration. These long-duration missions however, impose a high degree of technological, operational, physical and psychological challenges. Mars analog habitats, such as the Mars Desert Research Station (MDRS) in Utah (U.S.) are established to conduct field experiments, test new hardware, new operational concepts and study the social and crew teamwork dynamics in support to these future manned missions to the Red Planet.

The International Emerging Space Leaders (IESLs) Crew (or MDRS Crew 205) is composed by eight outstanding international space young professionals and students, who together, will undertake a Mars analog mission from February 9th to 24th at MDRS. The IESL’s Crew is an interdisciplinary and multicultural team including members from Kuwait, Spain, Germany, the U.K. and the U.S. During the two-week rotation, the crew will simulate a mission to the Red Planet.

The team will conduct multiple research projects relevant to space exploration in areas such as in-situ resources utilization, human behavior, leadership and teamwork, astronomy, geology, EVA optimization, and science outreach. In addition to these research projects, the crew will also be in charge of the maintenance of MDRS facilities and daily operations of the station. This mission will also ultimately contribute to a better understanding of the requirements, benefits and challenges of international teams in future manned missions.

Description by Maria Grulich, as it first appeared on imaggeo.egu.eu.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.