Aug 14, 2019

The rise in the Oceans' level has accelerated since the 1960s


By 2100, the global rise could be twice the expected growth compared to a normal projection  

Rise in the Ocean level, Chile.
City of Viña del Mar, Chile
Photo: laotravoz.org

The study of the Earth by satellites revealed that the sea level of the entire planet has been growing every year. The precise measurements, which began in the early 1990s, show that this rise has been accelerating since that date, mainly as a result of ice melting in Greenland and Antarctica. That is, not only sea level increases, but also increases faster and faster.

But what was not known was whether this acceleration had been occurring since before the measurements, nor where and why it would have originated in that case. Now, an international study has added new calculations to investigate the past, thanks to data provided by stations in  areas near the coastline. The results conclude that the acceleration of the sea level rise has been occurring since the 1960s and that they have influenced other factors besides the melting of ice.

The change in the oceans has been taking place for half a century. The new study, published by Nature Climate Change, indicates that the global sea level rise has increased from less than one millimeter per year in the 1960s to more than three millimeters per year today. 

Greenhouse gas emissions have been warming the planet around 1º from pre-industrial times until reaching the climate emergency we are in today. And that rise in temperature also causes the sea level to grow across the globe for two reasons. “There is an obvious one, the ice that melts and adds more water to the oceans; but another more complicated is the absorption of heat, which causes a thermal expansion of the water increasing its volume”, explains Francisco Mir Calafat, a researcher at the National Oceanography Centre of the United Kingdom and co-author of the study, together with Marta Marcos, from the Mediterranean Institute for Advanced Studies.

But, despite what one might think, this rise in sea level does not occur uniformly across the planet. There are other factors that influence that water and heat are redistributed by the Oceans unevenly, such as the course of the winds, the circulation of the waters and even the changes in the Earth's gravity field. In this case, according to the reports, the acceleration began to take shape in the South Pacific and the winds played a decisive role.

The new calculation not only serves to determine the acceleration in the past times, but also to alert what may happen in the future. The findings of this study highlight the important role that thermal expansion plays in the rate of sea level rise causing this acceleration, which had already been predicted by the 2013 Intergovernmental Panel on Climate Change for the 21st century. Thus, If we project the current conditions into the future, assuming that it will continue constant, the sea level increase could be more than double that expected for the year 2100, compared to projections that assume a normal increase rate. 


Heavy sea, Viña del Mar, Chile.
"Pacific" Ocean, Chile
Photo: revistaenfoque.cl
"The acceleration that occurs after the 90s is attributed to the melting of Antarctica and Greenland, but we see that it began in the 60s due to heat absorption," says Mir. He added: "The changes of the wind cause in turn changes in the circulation of the Ocean, which has led to this greater absorption of heat that causes the sea level to rise." In the subtropical South Pacific, East of Australia and New Zealand, the acceleration of the rise has been five times faster than the global average. For Mir, it is most likely that this alteration in the circulation of the roaring winds of the South has to do with climate change, but it is not something they have studied in this work.

"The new evaluation of the tide gauges shows an acceleration similar to that recorded by satellites from space in the last 25 years," says the geophysicist Carling Hay of Boston College, which means that the analysis of the study is robust. Researchers have developed a hybrid model that takes advantage of the global data of satellites and those offered by tide gauges, whose measurements are based on coastal points.

Translated by: Raul Silva M.
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Jul 27, 2019

A Wonder Called Torres del Paine


The nature reserve, declared a Biosphere Reserve by UNESCO and described as an idyllic landscape, became a National Park in 1959.



Horse ridings at Torres del Paine.
Photo: baqueanozamora.cl
Tourism company, Puerto Natales, Chile.

   The word "paradise" takes on all its meaning in Parque Nacional Torres del Paine: 227,298 hectares and an exceptional geography composed of imposing massifs, virgin forests and turquoise lakes. All this with a sky that acquires fantastic colors and invites you to discover the reason for the many awards it has received as one of the most beautiful places on the planet. 

Located 154 kilometers northwest of Puerto Natales and 399 kilometers from Punta Arenas, this nature sanctuary is located near Los Andes, at the southern tip of Chile. It was founded as Parque Nacional de Turismo Lago Grey on May 13, 1959, when the main regional activity was livestock and tourism was reduced to some few adventurers. 

On April 30, 1970 the park added 11,000 new hectares to its protected area and was renamed as it is known today. Since then, it has not stopped adding recognitions and tourists interested in knowing it. Within the Park's limits you'll find an imposing geography composed of massifs, lakes, icebergs, glaciers, rivers, oak forests typical of Tierra del Fuego and extensive pampas visited by guanacos, rheas and pumas.

A privileged environment that one of the first visitors defined as "one of the most spectacular landscapes that the human imagination can conceive." Every year, this place opens its doors to thousands of tourists looking for experiences in the midst of nature and with all kinds of comforts: marked trails, hiking and adventure activities, as well as accommodation and catering alternatives.

The name Torres comes from its two characteristic elevations, also called Cuernos del Paine, which are eroded remains of an elevated region, created by granite plutons that raise superimposed sedimentary layers of which the lowest is a dark red slate. Overlapping materials have eroded completely, leaving only several round and tall granite towers: the park's real towers. Some of the original materials remain and, as these have different gradients and colors, shaped the characteristic peaks.

According to studies conducted in the area, the Paleoindian utensils found around the park indicate that it was inhabited about 12,000 years ago by the Aonikenk. The Tehuelche Indians, descendants of the Paleoindians, later gave the name Paine to the massif, which means "blue" in their language. Since the fifteenth century the area has also been home to the Kaweskar who live with wild pumas, condors and guanacos.

Unfortunately, in recent decades the action of man has deteriorated the surroundings causing several forest fires which have consumed vast areas of vegetation.


 Photo: Vertice Patagonia
On February 10, 1985, a tourist threw a burning cigarette butt, which unleashed a fire that consumed about 14,000 hectares of the park. Twenty years later, another visitor knocked over a kitchenette and caused another fire that burned an area of more than 15,000 hectares, of which more than 11,000 directly affected the park. At the end of 2011, Torres del Paine National Park suffered a new forest fire that consumed more than 17,000 hectares, this time due to the bonfire made by another visitor.

Torres del Paine National Park, declared a Biosphere Reserve by UNESCO and chosen the eighth wonder of the world in 2013 by Virtual Tourist in a contest in which it received more than five million votes, has established itself as a tourist attraction and also as in an example of nature conservation.
 

Translated by: Raul Silva M.
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