Suivre ce blog
Administration Créer mon blog

Earth of fire

Actualité volcanique, Article de fond sur étude de volcan, tectonique, récits et photos de voyage


With the approach of the feast of the Nativity , it is good to be back on three births this year among the volcanic islands.

In the Izu- Bonin volcanic arc , the new Niijima island is still growing on the side of Nishino -shima in the Ogasawara islands. After the appearance on the surface of the cone between 21 and 25 November, the subaerial volcanic activity , characterized by sporadic Strombolian explosions and lava effusions , has continued to develop the island.
Two lava delta formed between late November and 10 December , and between 10 and 13 December. Its measurements are around 400 m. (E- O) at 300 m. (N -S ) .
 2103.12.13. Nijima - JCG
                        Niijima - photo Japan Coast Guards / 12/13/2013
new nishinoshima ryaku131213Niijima - contours of expansion : in yellow, 25/11/2013 - in red: 12.13.2013 situation, with the addition of lava deltas on both sides . - Doc . Japan Coast Guards.
new nishinoshima thermal131213
Niijima - thermal imaging targeting recent lava flows - docs . 12/17/2013 Japan Coast Guards

In the Red Sea , a submarine eruption in the volcanic group Jebel Zubair gave birth to a new island September 28, 2013 . The activity currently restarted on November 6, to continue at least until November 20 . The view from the satellites was then hidden a few days, and a Landsat 8 image taken on 24.11 leaves no view of activity .

jebel-zubair-24nov13 - Volcanodiscovery
Jebel Zubair - left, Google image before the eruption - right , photo taken by Landsat on November 24, 2013 - Doc. Volcanodiscovery
New-Island-Red-Sea - Capitalerythrea
         Geotectonic context of the region and position of the new island - doc . capital Erythrea

After the strong earthquake of M 7.7 that hit Pakistan on September 24 , a new island has emerged off Gwadar . Called Zalzala Jazeera ( earthquake island) , it is 152 m. on 182 m., and exceeds the sea level of 15-20 meters ( NASA EO- 1). The surface of the island is mostly muddy and its crust is covered with large boulders . Methane gas comes in various parts of the island, according to experts at the National Oceanographic Institute , suggesting a rise of mud and rocks to the surface under the pressure of gas released by the earthquake.

                            Zalzala Jazeera - 25/09/2013 - photo Getty Images

According to seismologists , this island is temporary and is expected to disintegrate rapidly under the combined effect of marine erosion and a reduction in gas pressure, before disappearing beneath the surface of the ocean.

A recent exploration of the area by the WWF Pakistan reveals a rich biodiversity appreciated by local fishermen. Four species of branching corals were also identified .
8-sia-600x400                  Zalzala Jazeera - Aerial View - NASA Earth Observatory

Acabaria delicatula - branching coral found on Zalzala Jazeera - photo WWF 's Abdul Rahim 22/11/2013



Sources :

- Niijima / on this blog : link

- Jebel Zubair / on this blog : link

- Zalzala Jazeera / on this blog : link

Articles récents

Hébergé par Overblog