How are aa and pahoehoe different? - Yahoo! Answers

--------------------

· Home
· Mail
· News
· Sports
· Finance
· Weather
· Games
· Groups
· Answers
· Flickr
· More

· omg!
· Shine
· Movies
· Music
· TV
· Health
· Shopping
· Travel
· Autos
· Homes

* Yahoo! Answers *

[INPUT][INPUT]

Sign In
Mail
/Help/

· Account Info
· Help
· Suggestions
· Send Feedback

Yahoo!

· Home
· Browse Categories

· Arts & Humanities
· Beauty & Style
· Business & Finance
· Cars & Transportation
· Computers & Internet
· Consumer Electronics
· Dining Out

· Education & Reference
· Entertainment & Music
· Environment
· Family & Relationships
· Food & Drink
· Games & Recreation
· Health

· Home & Garden
· Local Businesses
· News & Events
· Pets
· Politics & Government
· Pregnancy & Parenting

· Science & Mathematics
· Social Science
· Society & Culture
· Sports
· Travel
· Yahoo! Products

· My Activity

Sorry, you need to be Signed in to see this.

Not a member? Join Here.

· About

· How Answers Works
· Points & Levels
· Community Guidelines
· Leaderboard
· Suggestion Board
· Answers Blog

· *Ask*

What would you like to ask?

· *Answer*

· *Discover*

What are you looking for? Advanced Search

1. Home >
2. All Categories >
3. Science & Mathematics >
4. Earth Sciences & Geology >
5. Resolved Question

Nogi W Nogi W

* Member since:
May 15, 2008
* Total points:
36 (Level 1)

· Add Contact
· Block

*Resolved Question*

Show me another »

** How are aa and pahoehoe different? **

A Aa has rough, jagged surfaces, and pahoehoe has smooth, ropelike
surfaces.
B Aa has smooth, ropelike surfaces, and pahoehoe


Source: answers.yahoo.com/question/index?qid=20080520060013AAlT60d


how are aa and pahoehoe different


Pahoehoe and Aa Basalt, Page 8

--------------------

1. Education

About.com
Geology

[INPUT]

· Geology
· Basics
· Quakes, Volcanoes Etc
· Images & Maps
·

· Share
·

** Pahoehoe and Aa Basalt **

*Basalt Picture Gallery*

Both of these basalt flows have the same composition, but while they were
molten, the smooth pahoehoe lava was hotter than the jagged aa lava. (more
below)
" One recipe, two outcomes "
Photo courtesy jtu of Flickr under Creative Commons license.
Click the photo for the full-size version. This lava flow displays two
textures of lava that have the same composition. The ragged, clinkery form
on the left is called aa (or in more proper Hawaiian spelling, ‘a‘a). You
pronounce it "ah-ah." Perhaps it has that name because the rough surface of
the solidified lava can quickly cut your feet to ribbons, even with heavy
boots. In Iceland, this kind of lava is called apalhraun.

The lava on the right is shiny and smooth, and it has its own name, like aa
a Hawaiian word—pahoehoe. In Iceland, this kind of lava is called
helluhraun. Smooth is a relative term—some forms of pahoehoe can have a
surface as wrinkled as an elephant's trunk, but not at all jagged like aa.

What makes the exact same lava produce two different textures, pahoehoe and
aa, is the difference in the way they have flowed. Fresh basalt lava is
almost always smooth, liquid pahoehoe, but as it cools and crystallizes it
turns sticky—that is, more viscous. At some point the surface can't
stretch quickly enough to keep up with the movement of the flow's interior,
and it breaks and shreds like the crust of a loaf of bread. This can happen
simply from the lava growing cooler, or it can occur as the flow


Source: geology.about.com/od/more_igrocks/ig/basalt/aapahoehoe.htm

© 2005-2018 HaveYourSay.org