25 augusti 2018

Newberrykratern, Oregon, 19JUL2018


Newberrykratern, innefattande bland annat Paulina Peak, Lava Flow, Paulina Lake, East Lake och Paulina Falls.






"Newberry Volcano (also known as Newberry Caldera) is a large active shield-shaped stratovolcano located 35 miles (56 km) east of the major crest of the Cascade Range and about 20 miles (32 km) south of Bend, Oregon, within the Newberry National Volcanic Monument."

"Newberry Volcano possesses a large caldera 4 by 5 miles (6.4 km × 8.0 km) in diameter, called the Newberry Caldera. Within the caldera there are two lakes (Paulina Lake and East Lake). The volcano and its vicinity feature many pyroclastic cones, lava flows, and lava domes; it has more than 400 vents, the most of any volcano in the contiguous United States."

"Eruptive activity began about 600,000 years ago, and has continued into the Holocene, its last eruption taking place 1,300 years ago."

"Still considered an active volcano, it could erupt and produce lava flows, pyroclastic flows, lahars (volcanically induced mudslides, landslides, and debris flows), ashfall, earthquakes, avalanches, and floods. To monitor this threat, the volcano and its surroundings are closely monitored with sensors by the United States Geological Survey."

" Multiple eruptions created the caldera, but the main caldera-forming event occurred around 75,000 years ago from a major explosive eruption. It formed the crater lakes and Paulina Peak, which is the highest point on the volcano, at 7,989 feet (2,435 m)."

" Newberry Volcano has also produced a number of Plinian eruptions similar to the eruption of Vesuvius that destroyed Pompeii, rising 20 miles (32 km) or more into the stratosphere. The last of these eruptions covered tens of thousands of square miles with ash, extending to the San Francisco Bay Area in California, nearly 500 miles (800 km) to the southwest."

"1,300 years ago, the volcano underwent its most recent eruptions, producing the Big Obsidian flow. A silicic deposit, it is made up of rhyolite and features a number of lava blocks."

"Though Newberry Volcano is currently quiet, the United States Geological Survey considers it an active volcano with a "very high" threat level. Hot springs within the caldera remain active, and small earthquakes have occurred within recent local history. Any future eruptions would likely show similar characteristics to eruptions from the past 15,000 years, ranging from effusive production of lava flows to explosive eruptions ejecting pumice and ash. Lava flows from Newberry Volcano of comparable size to its late Pleistocene eruptions would bury settlements throughout the Central Oregon region."

"The trail to the volcano's summit at Paulina Peak lasts 15.5 miles (24.9 km) from Highway 97, with an easy paved road to the caldera and four rest stops, though it grows steep and twisty near the end. The winding trail near the end is made of gravel, and lasts for 3 miles (4.8 km), offering views of Mount Hood, Mount McLoughlin, and the Three Sisters volcanoes."

https://en.wikipedia.org/wiki/Newberry_Volcano

Paulina Peak
Höjd över havet: 2 434 meter
Höjd över närliggande omgivning: 980 meter

https://en.wikipedia.org/wiki/Paulina_Peak

På väg upp till Paulina Peak.


Utsikt från Paulina Peak.


Det stelnade lavaflödet sett uppifrån Paulina Peak.


Lavaflödets slut vid skogskanten.



Obsidian.

Promenadstigen inne i lavaflödet.





East Lake:



Paulina Falls:



23 augusti 2018

Crater Lake och Mount Scott, Oregon, 18JUL2018

Några bilder från besöket vid vackra Crater Lake i Oregon i USA och promenaden upp till toppen på det närbelägna Mount Scott. Vi körde från San Francisco till Klamath Falls, där vi stannade över natten. Nästa dag upp längs US97. Stannade till I Chiloquin för att handla lite, sedan in på OR62 mot Crater Lake.







Crater Lake bildades för ungefär 7500 år sedan då den vulkan som numer kallas Mount Mazama exploderade och kollapsade. Sedan dess har kratern fyllts med regnvatten och smält snö och is. Den har inga andra tillflöden av vatten. Den lilla ön i sjön som syns på några av bilderna heter Wizzard Island och är i sig själv en vulkan. Man kan åka båt dit ut och gå upp till toppen, men vi gjorde inte det. 

"The caldera was created in a massive volcanic eruption between 6,000 and 8,000 years ago that led to the subsidence of Mount Mazama. About 50 cubic kilometers (12 cu mi) of rhyodacite was erupted in this event. Eventually, the caldera cooled, allowing rain and snow to accumulate and form a lake.

 It is estimated that about 720 years was required to fill the lake to its present depth of 594 metres (1,949 ft). Some hydrothermal activity remains along the lake floor, suggesting that at some time in the future, Mazama may erupt once again."


Länk: 

https://en.wikipedia.org/wiki/Crater_Lake

Mt Scott är 2 721 meter över havet, men Crater Lake själv ligger på drygt 1 800 meter över havet så höjdskillnaden är inte så stor.

"Mount Scott is a small stratovolcano and a so-called parasitic cone on the southeast flank of Crater Lake in southern Oregon. It is approximately 420,000 years old. Since it was relatively far away from the main flanks of Mount Mazama, it survived the mountain's massive explosion that occurred around 5700 BC. There is one trail to the summit of Mount Scott. Starting on Rim Drive, the trail is about 4.0 km long. It has many switchbacks, and ends at the fire lookout tower on the summit. The trailhead is at an elevation of 2,342 m, and the trail climbs approximately 451 m to the top of Mount Scott at 2,723 m."

Länk:

https://en.wikipedia.org/wiki/Mount_Scott_(Klamath_County,_Oregon)

Promenden tog ungefär tre kvart upp till toppen. Den är inte alltför ansträngande men man bör vara i åtminstone ordinärt skaplig form och man bör ha vatten med sig och bra skor på sig. Den börjar svagt uppåt genom ett skogsparti för att sedan bli brantare i takt med att landskapet på bergets sluttningar blir kargare. Så småningom övergår stigen till att gå i zick-zack nästan ända upp till toppen. Sista biten är enkel längs en ås utan någon vidare stigning norrut mot högsta punkten där det ligger en gammal vädestation. Utsikten från toppen över Crater Lake och övriga Oregon är magnifik. Långt söderut syns Mount Shasta i Kalifornien. Vädret var fint när vi var där, med generellt klar sikt men något disigare uppe från toppen på grund av flera skogsbränder runtom i Oregon.




















09 mars 2014

Testar Nikon D5300



27 februari 2014:




28 februari 2014:


2 mars 2014:







9 mars 2014: