Przejdź do zawartości

Plik:Tahiti, French Polynesia - NASA Earth Observatory.jpg

Treść strony nie jest dostępna w innych językach.
Z Wikisłownika – wolnego słownika wielojęzycznego

Tahiti,_French_Polynesia_-_NASA_Earth_Observatory.jpg (720 × 480 pikseli, rozmiar pliku: 137 KB, typ MIME: image/jpeg)

Opis

Opis

To download the full resolution and other files go to: earthobservatory.nasa.gov/IOTD/view.php?id=78218&src=...

In August 1768, Captain James Cook, naturalist Joseph Banks, and a shipload of sailors set sail from England to Tahiti to observe the Transit of Venus. Camped out on Point Venus, they witnessed the event on June 3, 1769. Cook sketched the transit, but Banks had surprisingly little to say about it. Perhaps he was distracted by the wonders of the island itself.

The Enhanced Thematic Mapper Plus on the Landsat 7 satellite captured this natural-color image of Tahiti on July 11, 2001. This island is part of a volcanic chain formed by the northwestward movement of the Pacific Plate over a fixed hotspot. Tahiti consists of two old volcanoes—Tahiti-Nui in the northwest and Tahiti-Iti in the southeast—linked by an isthmus.

Through studies of its rock layers, geologists have figured out the likely history of Tahiti-Nui. Today it is roughly round, and it was roughly round when it first formed as a volcanic shield between 1.4 million and 870,000 years ago. But between then and now, it had a different contour. Both the northern and southern flanks of Tahiti-Nui collapsed sometime around 860,000 years ago, gouging massive arcs out of the island’s perimeter. Soon after the northern flank collapse, a second shield volcano began forming. Volcanic material on the northern side of Tahiti-Nui eventually overtopped the original volcanic structure and started filling in the southern depression.

Although Tahiti-Nui now has a fairly symmetrical contour, it has an asymmetrical three-dimensional shape. Mountains are taller on the northern half of the island.

Yet something else besides volcanic activity has shaped Tahiti: rain. Heavy tropical rains have carved deep valleys, some with nearly vertical walls up to 1,000 meters (3,000 feet) tall. The angled sunlight in this image brightens some slopes, while leaving others in shadow. Tahiti’s sharp relief has complicated the geological surveys because they cause so much erosion. But the same rains have also promoted the growth of the lush plants that carpet both Tahiti-Nui and Tahiti-Iti.

Though the Transit of Venus was the stated objective of the British expedition, Banks was likely more interested in Tahiti’s plants. Specimens he collected from Tahiti, New Zealand, South America, Australia, and Java accounted for roughly 1,300 new species, and his famed collected is now stored at the Natural History Museum in London.

Complementing the rich life on land is marine life around Tahiti’s perimeter. Coral reefs fringe the island, and the reefs are thickest on the southern and western sides. Reefs frequently form along the submerged slopes of volcanic islands.

NASA Earth Observatory image by Jesse Allen and Robert Simmon, using Landsat data from the U.S. Geological Survey. Caption by Michon Scott.

The Earth Observatory's mission is to share with the public the images, stories, and discoveries about climate and the environment that emerge from NASA research, including its satellite missions, in-the-field research, and climate models.

Like us on Facebook

Follow us on Twitter

Add us to your circles on Google
Data
Źródło Tahiti, French Polynesia
Autor NASA's Earth Observatory
Pozycja fotografa17° 41′ 24,61″ S, 149° 22′ 33,63″ W Kartographer map based on OpenStreetMap.To i inne zdjęcia na: OpenStreetMapinfo

Licencja

w:pl:Licencje Creative Commons
uznanie autorstwa
Ten plik udostępniony jest na licencji Creative Commons Uznanie autorstwa 2.0.
Wolno:
  • dzielić się – kopiować, rozpowszechniać, odtwarzać i wykonywać utwór
  • modyfikować – tworzyć utwory zależne
Na następujących warunkach:
  • uznanie autorstwa – musisz określić autorstwo utworu, podać link do licencji, a także wskazać czy utwór został zmieniony. Możesz to zrobić w każdy rozsądny sposób, o ile nie będzie to sugerować, że licencjodawca popiera Ciebie lub Twoje użycie utworu.
Ten plik, opublikowany pierwotnie w serwisie Flickr przez NASA Earth Observatory pod adresem https://www.flickr.com/photos/68824346@N02/7180520297, został sprawdzony 2 lipca 2012 przez FlickreviewR, który potwierdził, że jest on tam dostępny na licencji cc-by-2.0.

2 lipca 2012

Podpisy

Dodaj jednolinijkowe objaśnienie tego, co ten plik pokazuje

Obiekty przedstawione na tym zdjęciu

przedstawia

17°41'24.612"S, 149°22'33.625"W

Historia pliku

Kliknij na datę/czas, aby zobaczyć, jak plik wyglądał w tym czasie.

Data i czasMiniaturaWymiaryUżytkownikOpis
aktualny18:01, 2 lip 2012Miniatura wersji z 18:01, 2 lip 2012720 × 480 (137 KB)Dzlinker== {{int:filedesc}} == {{Information |Description=To download the full resolution and other files go to: [http://earthobservatory.nasa.gov/IOTD/view.php?id=78218&src=flickr earthobservatory.nasa.gov/IOTD/view.php?id=78218&src=...] In August 1768, Capt...

Następujące strony korzystają z tego pliku:

Globalne wykorzystanie pliku

Ten plik jest wykorzystywany także w innych projektach wiki:

Metadane