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Basic features of the arctic
Cold Regions Science and Technology, 7 (1983) 27--32 Elsevier Science Publishers B.V., A m s t e r d a m - - Printed in T h e N e t h e r l a n d s
Basic Features of the Arctic Tore Gjelsvik Norwegian Polar Research Institute, Oslo
Abstract
Introduction
77~e basic f e a t u r e s of the Arctic are caused in parr by the g e o m a g n e t i c relationships, in part by the i n c l i n a t i o n of the axis of the earth in relation to its orbit, as well as by the physiographic and topographic conditions.
W h a t is t h e A r c t i c ? B e i n g a s k e d t h i s q u e s t i o n , most people think about the area around the N o r t h Pole as a r e g i o n w i t h c o m p l e t e w i n t e r d a r k n e s s or m i d n i g h t sun, p o l a r b e a r s a n d r e i n deer, e s k i m o s , t u n d r a a n d p e r m a f r o s t , a n d a cold a n d h a r s h c l i m a t e - - g e n e r a l l y , s o m e t h i n g i n h o s p i t a b l e a n d u n p l e a s a n t . T h o s e of u s w h o k n o w t h e A r c t i c feel d i f f e r e n t a l t h o u g h a t t i m e s w e a d m i t it c a n b e r o u g h up t h e r e . To u s t h e A r c t i c is a n a r e a of u n b e l i e v a b l e b e a u t y a n d solitude, of d r e a m s a n d c h a l l e n g e .
To start f r o m the very top: the g e o m a g n e t i c condition allows interaction b e t w e e n solar plasma and the u p p e r atmosphere, causing m a g n e t i c storms and aurora which disturb magnetic m e a s u r e m e n t s and the propagation of the radio waves. This gives n a v i g a t i o n and c o m m u n i c a t i o n difficulties. However, it also m a k e s the Arctic a m o s t i m p o r t a n t scientific u'indow to the outer space. The geography of the Arctic can be described as a centrally located ocean, surrounded by low land and a f e w high m o u n t a i n ranges and narrow straits leading to the world oceans. In this way it differs f u n d a m e n t a l l y f r o m the Antarctic, which is a c o n t i n e n t surrounded by a big ocean. The Arctic climate, although polar, is less severe than the A n t a r c t i c one. The f e a t u r e s of the Arctic, w h i c h give m o s t problems to the a c t i v i t i e s of man, are of two types: the p e r m a n e n t p a c k ice f i l l i n g up the Arctic Basin and e x p a n d i n g into a d j a c e n t seas during winter, the p e r m a f r o s t and particularly the t h a w i n g during the s u m m e r of the 1--2 m thick u p p e r m o s t layers of the soil. In addition to the description of the geophysical characteristics of the various A r c t i c regions or zones m e n t i o n is made of biologic features, the i n d i g e n o u s people and of e n v i r o n m e n t a l matters. 0165-232X/83/$03.00
FIGURE 1.
© 1 9 8 3 Elsevier Science Publishers B.V.
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These are the feelings, what are the realities? In o r d e r to d e s c r i b e t h e m , o n e h a s to d e f i n e t h e b o r d e r s of t h e Arctic. S o m e p e o p l e u s e t h e latit u d e s s u c h as t h e A r c t i c circle or t h e 60's d e g r e e N. In t h e U.S. o r C a n a d a t h e l a t t e r is o f t e n used, w h i c h m e a n s t h a t e v e n m o s t of s o u t h e r n N o r w a y is i n c l u d e d . A n y o n e h a v i n g s w e a t e d through the tropical temperatures during last s u m m e r h e r e in Oslo, will h a v e d i f f i c u l t i e s in accepting that definition. There are other a l t e r n a t i v e s s u c h as t h e n o r t h e r n t r e e line or t h e l i m i t of c o n t i n e o u s p e r m a f r o s t in t h e lowlands. N o n e of t h e s e g i v e s u s a b o r d e r l i n e in t h e sea. I p r e f e r to u s e t h e + 10°C i s o t h e r m for t h e w a r m e s t m o n t h , July, w h i c h c o i n c i d e s r e l a t i v e l y well w i t h t h e t r e e line, a n d w h i c h is s h o w n in Fig. 1. A c c o r d i n g to t h i s d e f i n i t i o n , t h e A r c t i c c o m p r i s e s 14 mill. s q u a r e k m s of s e a a n d 8 of land.
Cosmic Geophysics In d e s c r i b i n g t h e b a s i c f e a t u r e s of t h e Arctic, I w o u l d l i k e to s t a r t f r o m t h e v e r y top, t h e u p p e r a t m o s p h e r e a n d t h e n e a r - e a r t h s p a c e in p o l a r r e g i o n s . Fig. 2 s h o w s a s k e t c h of t h e e a r t h ' s m a g n e t i c field e n v e l o p e a n d of t h e f l o w l i n e s of t h e s o l a r wind. T h e e n e r g e t i c p a r t i c l e s of t h e s o l a r w i n d a r e p i c k e d u p b y t h e m a g n e t i c field l i n e s a n d d i r e c t e d t o w a r d s t h e p o l a r caps, w h e r e t h e y i n t e r a c t w i t h a t o m s of t h e u p p e r a t m o s p h e r e to p r o d u c e t h e b e a u t i f u l p o l a r lights, or
w,~
FIGURE 2.
28
S k e t c h of the Earth's m a g n e t i c - f i e l d envelope, or m a g n e t o s p h e r e , and its c o n n e c t i o n to the p o l a r regions (not to scale). R e l e v a n t p l a s m a regions a n d s a m p l e m a g n e t i c f i e l d lines c o n n e c t i n g the p o l a r cap to the i n t e r p l a n e t a r y f i e l d are shown.
aurora, but at the same time disturb the m a g n e t i c field a n d r a d i o e m i s s i o n s . B e f o r e t h e satellites were introduced, telecommunication a n d n a v i g a t i o n in t h e h i g h a r c t i c w e r e r a t h e r difficult. N o r t h of a p p r o x i m a t e l y 78 d e g r e e s N, s a t e l l i t e t e l e c o m m u n i c a t i o n is still n o t p o s s i b l e . A t t h e s a m e t i m e , t h e s e e f f e c t s h a v e m a d e it p o s s i b l e f o r c o s m i c p h y s i c i s t s a n d s p a c e scientists to o b s e r v e d i r e c t l y m a n i f e s t a t i o n s of p h e n o m e n a o c c u r r i n g in t h e d e e p s p a c e . T h e p o l a r a r e a s h a v e t h u s b e c o m e t h e E a r t h ' s w i n d o w for r e m o t e s e n s i n g a n d o t h e r s t u d i e s of t h e s p a c e a n d its e f f e c t s on o u r e n v i r o n m e n t .
Physiography T h e A r c t i c m a y b r i e f l y be d e s c r i b e d a s a pere n n i a l l y ice-covered, d e e p ocean, s u r r o u n d e d b y i s l a n d s , c o n t i n e n t a l c o a s t a l a r e a s , a n d of peripheral , seasonally ice-covered seas. The landm a s s e s m o s t l y c o n s i s t of l o w l a n d . H i g h m o u n t a i n r a n g e s a r e f o u n d o n l y in A l a s k a , e a s t e r n m o s t S i b e r i a a n d C a n a d a , a n d in G r e e n l a n d . T h e b o t t o m of t h e p e r i p h e r a l s e a s c o n s i s t s l a r g e l y of e x t e n s i v e a n d s h a l l o w c o n t i n e n t a l shelves. T h e t h r e e to five t h o u s a n d m d e e p p o l a r b a s i n h a s a r a t h e r c o m p l i c a t e d m o r p h o l o g y . It is i n t e r s e c t e d b y two m a j o r s u b s e a m o u n t a i n r i d g e s called the Alpha-Mendeleyev-Ridge and the L o m o n o s o v Ridge, t h e l a t t e r c r o s s i n g n e a r t h e N o r t h Pole w i t h a c r e s t of 1000 to 1500 m b e l o w s u r f a c e . A m e d i a n rift v a l l e y s p l i t s t h e b a s i n on t h e E u r a s i a n side of t h e L o m o n o s o v R i d g e in two s u b - b a s i n s . T h e 500 k m w i d e a n d 2500 m deep F r a m S t r a i t b e t w e e n G r e e n l a n d a n d Svalb a r d p r o v i d e s t h e m o s t i m p o r t a n t c h a n n e l for e x c h a n g e of w a t e r b e t w e e n t h e p o l a r b a s i n a n d the world oceans. The Polar Ocean constantly receives fresh water from the big north-flowing Siberian and Canadian rivers, giving a brackish s u r f a c e l a y e r t h a t e n h a n c e s t h e f o r m a t i o n of ice. A l o n g t h e e a s t side of t h e F r a m S t r a i t w a r m a t l a n t i c w a t e r e n t e r s t h e p o l a r b a s i n . To b a l a n c e these inputs, the excess water and large masses of p o l a r p a c k i c e flow s o u t h a l o n g t h e o p p o s i t e side of t h e s t r a i t .
Geology O n l y a c c e s s i b l e p a r t s of t h e A r c t i c c o n t i n e n t a l s h e l v e s a n d t h e floor of s o m e p e r i p e h e r a l s e a s h a v e b e e n s u b j e c t e d to s y s t e m a t i c g e o l o g i c a l s u r v e y s up to now. In t h o s e p a r t s t h e b a s e m e n t is c o v e r e d b y f r o m 2 to m o r e t h a n 10 k m of sedi-
ments, with a substantial hydrocarbon potential in s o m e areas. T h i s a s p e c t will be t r e a t e d b y later speakers. From the central, perennially ice-covered b a s i n the d a t a are few, u n e v e n l y dist r i b u t e d a n d p r e l i m i n a r y . W h a t w e know, is based u p o n m e a s u r e m e n t s f r o m Soviet, U.S. a n d c a n a d i a n scientific s t a t i o n s of f l o a t i n g ice a n d from airborne geophysical surveys. In general the b a s e m e n t of t h e Arctic sea floor s e e m s to be covered by s e d i m e n t a r y s e q u e n c e s of 2 k m t h i c k n e s s , w h i c h is m o r e t h a n i n a n y o t h e r o c e a n b a s i n . I n s o m e places, e v e n 5 k m or m o r e of s e d i m e n t s h a v e b e e n i n f e r r e d . I n t h e C a n a d a basin the layers thicken seawards, and s t r u c t u r a l t r a p s h a v e b e e n o b s e r v e d . T h e Lomon o s o v R i d g e is b y m o s t s c i e n t i s t s c o n s i d e r e d a f r a g m e n t of t h e E u r a s i a n c o n t i n e n t a l shelf. T h e o r i g i n of t h e A l p h a - M e n d e l e y e v - R i d g e is m o r e q u e s t i o n a b l e . A l t h o u g h s o m e s c i e n t i s t s are i n f a v o u r of a c o n t i n e n t a l crust, it m u s t be s t u d i e d in m o r e d e t a i l b e f o r e safe c o n c l u s i o n s c a n be drawn.
Biology Biological c o n d i t i o n s in t h e Arctic a r e c h a r a c t e r i z e d by low p r i m a r y p r o d u c t i o n ( a l t h o u g h in s o m e arctic a n d s u b - a r c t i c seas it c a n be high), a n d e c o s y s t e m s w i t h few species a n d populat i o n s r a n g i n g f r o m few to v e r y a b u n d a n t . T h e y often show r e m a r k a b l e b e h a v i o r a l a d a p t a t i o n s , high v u l n e r a b i l i t y to c h a n g e , a n d slow r e c o v e r y if locally d i s r u p t e d , b u t a r e t o u g h over t h e Arctic as a whole.
Climate T h e p o p u l a r c o n c e p t of t h e Arctic as a r e g i o n of p e r p e t u a l b i t t e r cold a n d deep s n o w is r a t h e r incorrect. T h e e x t r e m e t e m p e r a t u r e s a n d snowfalls are f o u n d i n t h e arctic b o r d e r l a n d s or e v e n in the s u b - a r c t i c areas. T h e m e a n air t e m p e r a t u r e over the Arctic b a s i n d u r i n g w i n t e r is - 3 0 to - 35 ~C, the lowest r e a d i n g s a r o u n d - 50°C. I n the s u m m e r , s u r f a c e air t e m p e r a t u r e s are n e a r the f r e e z i n g p o i n t a n d m a y go u p to a few d e g r e e s a v b o v e it (Fig. 3). A n n u a l p r e c i p i t a t i o n is v e r y low, 100 to 150 m m , m o s t of it f a l l i n g in t h e s u m m e r or a u t u m n . Low clouds a n d fog are a c o m m o n nuisance, especially during the summ e r s e a s o n . W i n d s are m o d e r a t e to low. T h e c l i m a t e of t h e Arctic as a w h o l e is d e p e n d e n t o n a n u m b e r of factors, s u c h as: t h e lati-
FIGURE 3.
t u d e s d e t e r m i n i n g solar a l t i t u d e a n d t h e l e n g t h of the day; the p r o p o r t i o n of l a n d a n d sea a n d of ice-covered a n d o p e n w a t e r s ; t h e d i s t r i b u t i o n a n d t e m p e r a t u r e s of o c e a n c u r r e n t s ; t h e proportion of s n o w - c o v e r e d a n d b a r r e n s u r f a c e s o n l a n d as well as of the a r e a l e x t e n s i o n of the s e a 29
ice; t h e t o p o g r a p h y of t h e l a n d a r e a s . C l o s e l y r e l a t e d to m o s t of t h e s e f a c t o r s a r e t h e freq u e n c y , i n t e n s i t y a n d t r a c k s of t h e c y c l o n e s . T h e i n t e r a c t i o n of all t h e s e f a c t o r s g i v e s r i s e to a v a r i e t y of c l i m a t e r e g i m e s in t h e p e r i p h e r a l a r c t i c r e g i o n s . L a r g e p a r t s of G r e e n l a n d h a v e t e m p e r a t u r e s a b o u t 10°colder t h a n t h e c e n t r a l Arctic, b o t h in t h e s u m m e r a n d w i n t e r , p r i m a r i ly b e c a u s e of t h e h e i g h t of t h e ice cap. A n n u a l p r e c i p i t a t i o n is v e r y low e x c e p t for t h e s o u t h e r n a n d w e s t e r n p a r t s , w h e r e it is a r o u n d 500 m m . South-western Greenland has a moister and m i l d e r c l i m a t e , m o d e r a t e d b y t h e n e a r b y icef r e e o c e a n . T h e c o a s t a l a r e a s of n o r t h A m e r i c a a n d E u r a s i a h a v e c o n t i n e n t a l c l i m a t e , i.e. d r y a n d cold w i n t e r s a n d m i l d s u m m e r s . D u r i n g s u m m e r t h e g r e a t t e m p e r a t u r e c o n t r a s t bet w e e n t h e cold A r c t i c O c e a n a n d t h e w a r m i n t e r ior l a n d m a s s e s g i v e s v a r i a b l e w e a t h e r w i t h average temperatures around +10°C, but hotter s p e l l s m a y occur. P r e c i p i t a t i o n is r a t h e r low, m o s t l y b e t w e e n 100 a n d 250 m m . The Svalbard area experiences rather special w e a t h e r : T h a n k s to t h e n o r t h - t r e n d i n g , w a r m o c e a n c u r r e n t a n d t h e c y c l o n i c a c t i v i t y in t h e N o r w e g i a n a n d B a r e n t s seas, m u c h h i g h e r t e m p e r a t u r e s o c c u r d u r i n g w i n t e r t h a n s h o u l d be e x p e c t e d at t h e s e h i g h l a t i t u d e s . O p e n w a t e r t h e r e f o r e e x i s t s o u t s i d e t h e w e s t c o a s t of S p i t s b e r g e n up to a b o u t 80 d e g r e e s N all y e a r r o u n d . A v e r a g e w i n t e r t e m p e r a t u r e s on t h e w e s t c o a s t of S p i t s b e r g e n , a t 78 d e g r e e s N, is a b o u t 15°C w a r m e r t h a n a t C a p e C h e l y u s k i n a t t h e s a m e lat i t u d e in S i b e r i a . In t h e w i n t e r a n d s p r i n g , h i g h p r e s s u r e a r e a s w i t h cold a r c t i c a i r m a s s e s m a y f r e q u e n t l y d o m i n a t e t h e w e a t h e r s i t u a t i o n in S v a l b a r d . Thus, g r e a t t e m p e r a t u r e v a r i a t i o n s a r e t y p i c a l , too, a n d e v e n a t h i g h a l t i t u d e s r a i n c a n fall in w i n t e r t i m e . P r e c i p i t a t i o n is h i g h e r t h a n in m o s t o t h e r a r c t i c a r e a s , e s p e c i a l l y on g l a c i e r s l o p e s on t h e e a s t side, w h e r e it m a y r e a c h 1000 m m a n n u a l l y . T h e s t r o n g e s t w i n d s in t h e A r c t i c o c c u r in s o u t h G r e e n l a n d a n d in t h e N o r w e g i a n a n d B a r e n t s seas.
Ice T h e f o r m a t i o n of ice a t s e a a n d on l a n d a r e t h e m o s t i m p o r t a n t c l i m a t i c e f f e c t s for t h e dev e l o p m e n t of a r c t i c e n e r g y r e s o u r c e s . T h e s e a ice c o v e r s on t h e a v e r a g e a m i n i m u m of 5.2 m i l l s q u a r e k m in S e p t e m b e r a n d a m a x i m u m of 11.7 mill s q u a r e k m in M a r c h - A p r i l (Fig. 4). O n l y a s m a l l p a r t is s m o o t h f a s t ice, up to a c o u p l e of m t h i c k n e s s f o r m e d in t h e w i n t e r in n e a r - s h o r e 30
FIGURE 4. . . . . Average minimum extent of sea ice ......... Average maximum extent of sea ice a r e a s , a n d l a r g e l y m e l t i n g in t h e s u m m e r time. M o s t of it is m o v i n g ice - - p a c k i c e - - w i t h a t h i c k n e s s of 2 to 6 m d e p e n d i n g u p o n a g e a n d location. D u e to w i n d p r e s s u r e , tide a n d o c e a n curr e n t s t h i s ice is in c o n s t a n t m o t i o n , f o r m i n g h i g h p r e s s u r e r i d g e s of ice r u b b l e , a n d o p e n l e a d s in a c o n f u s i n g p a t t e r n . V a r i a t i o n s in size a n d a g e of t h e ice floes c a n be c o n s i d e r a b l e within short distances. Pressure ridges are m o s t l y 1-2 m high, m a x . 15 m, a n d m a y e x t e n d to a d e p t h of 50 m u n d e r t h e s u r f a c e . In t h e B e a u f o r t S e a t h e p a c k i c e m o v e s in a g r e a t g y r e w i t h low s p e e d s in t h e c e n t r e , a n d increasing outwards. In the Eurasian basin, the ice g e n e r a l l y m o v e s w i t h a n a v e r a g e s p e e d of 3 cm/sec from the siberian Shelf towards the F r a m S t r a i t w h e r e t h e s p e e d a c c e l e r a t e s to 10-15 c m / s e c . A l o n g t h e b o r d e r s , s m a l l e r g y r e s a r e f o r m e d . T h e w i n t e r ice is h a r d a n d tough, in the summer the surface gets slushy and puddled, making surface transport and airplane l a n d i n g difficult a n d h a z a r d o u s . In m o s t of t h e a r c t i c h i g h l a n d s , g l a c i e r s a r e u b i q u i t o u s , t h e G r e e n l a n d ice c a p b e i n g b y f a r t h e m o s t i m p o r t a n t , c o v e r i n g a n a r e a of 1.7 mill s q u a r e k m w i t h u p to m o r e t h a n 3 k m d e p t h . G l a c i e r s u r g e s of h i g h s p e e d , up to 35 m p e r d a y ,
a r e n o t u n c o m m o n in a r c t i c m o u n t a i n o u s a r e a s . G r e a t e r d a n g e r to h u m a n a c t i v i t y s t e m s f r o m i c e b e r g s c a l v i n g f r o m f i o r d g l a c i e r s , ice c a p s a n d ice s h e l v e s . T h e l a r g e s t a r e t h e r a r e t a b u l a r iceb e r g s w h i c h m a y b e u p to 30 k m w i d e a n d 60 m thick, b u t also t h e i r r e g u l a r i c e b e r g s c a n b e large a n d h a v e e v e n d e e p e r d r a f t s , up to 450 m. M o s t of t h e m a r e f r o m G r e e n l a n d a n d E l l e s m e re L a n d . Q u i t e a few a r e c a r r i e d s o u t h w a r d s into t h e s h i p p i n g l a n e s of t h e N o r t h A t l a n t i c b y t h e s w i f t e a s t G r e e n l a n d c u r r e n t or a l o n g t h e c o a s t of L a b r a d o r . F u t u r e p e t r o l e u m a c t i v i t y on t h e e a s t G r e e n l a n d c o n t i n e n t a l s h e l f will no d o u b t be g r e a t l y d i s t u r b e d b y t h e m , b u t i c e b e r g s on t h e e a s t side of t h e S v a l b a r d a r c h i p e l a g o s h o u l d not be d i s r e g a r d e d , e i t h e r .
Permafrost Perennially frozen ground -- permafrost -occurs where the ground temperature remains c o n s t a n t l y b e l o w 0°C o v e r a p e r i o d of y e a r s . Its d e p t h d e p e n d s on t h e a v e r a g e a n n u a l t e m p e r a ture, t h e t o p o g r a p h y a n d t h e l e n g t h of t i m e of t h e n e g a t i v e t e m p e r a t u r e b a l a n c e . O r d i n a r i l y , it is a b s e n t u n d e r g l a c i e r s a n d sea, a l t h o u g h it m a y b e p r e s e n t u n d e r s h a l l o w a n d cold seas, possibly as a relic from the time when the sea level w a s l o w e r t h a n t o d a y . T h e t h i c k e s t p e r m a f r o s t - - 1500 m - - is r e c o r d e d in S i b e r i a . F r o m C a n a d a 600 m is r e p o r t e d . I n c e n t r a l S p i t s b e r g e n , 3-400 m is f o u n d u n d e r t h e m o u n t a i n s , 100-200 m u n d e r t h e v a l l e y s . Ice is c o n c e n t r a t e d in t h e p o r e s of u n c o n s o l i d a t e d s e d i m e n t s , b u t also in w e d g e s a n d s h e e t s ( g r o u n d ice). D u r i n g s u m m e r t h e s u r f a c e l a y e r s will m e l t to a d e p t h of 1-2 m, m a x i m u m 5. T h i s s o - c a l l e d a c t i v e l a y e r is b i o l o g i c a l l y v e r y i m p o r t a n t , s i n c e it s u p p o r t s a s p a r s e v e g e t a t i o n . D u e to t h e i m p e r m e a b i l i t y of t h e p e r m a f r o s t below, t h e s u r f a c e l a y e r g e t s v e r y w e t a n d r e p r e s e n t s a s e r i o u s p r o b l e m for g r o u n d t r a n s p o r t a t i o n a n d c o n s t r u c t i o n w o r k in t h e Arctic. T h e a l t e r n a t i o n of t h a w i n g a n d freezing p r o d u c e s v e r y s t r i k i n g s t r u c t u r e s in a r c t i c soils, c a l l e d p a t t e r n e d g r o u n d . T h e m a t e r i a l is o f t e n s o r t e d a c c o r d i n g to size, s t o n e s a r e c o n c e n t r a t e d a n d o r i e n t e d in p o l y g o n s or rings, s o m e e e n t i m e t r e s to t e n t h of m e t r e s a c r o s s , w i t h t h e f i n e r m a t e r i a l in t h e m i d d l e . O n s l o p i n g hills, t h e w h o l e a c t i v e l a y e r s l i d e s b y g r a v i t y (solifluction), a n d t h e p a t t e r n e d s t r u c t u r e s a r e d r a w n o u t to p a r a l l e l s t r i p e s or b a n d s . T h e f r e q u e n t f r e e z i n g a n d t h a w i n g l e a d to a n e x t e n sive f r a c t u r i n g of t h e s u r f a c e s of e x p o s e d r o c k s .
Thus, in t h e Arctic, m e c h a n i c a l d i s i n t e g r a t i o n g r e a t l y o u t w e i g h s c h e m i c a l p r o c e s s e s in t h e w e a t h e r i n g of r o c k s . In c o m b i n a t i o n w i t h s l u s h flow, s o l i f l u c t u i o n , r i v e r a n d g l a c i a l e r o s i o n t h i s r e s u l t s in a r a p i d d e n u d a t i o n of m o u n t a i n s . T h e v e r y m u d d y r i v e r s d e p o s i t t h e i r l o a d in l o w e r valleys, deltas and other near-shore areas. Tides, c u r r e n t s a n d ice s c o u r r a p i d l y a l t e r s t h e c o n f i g u r a t i o n of c o a s t l i n e s .
Other resources T h i s c o n f e r e n c e is f o c u s e d u p o n t h e A r c t i c e n e r g y r e s o u r c e s . H o w e v e r , it s h o u l d n o t be forgot t h a t t h e A r c t i c also c o n t a i n s o t h e r i m p o r t a n t m i n e r a l r e s o u r c e s , as w e l l as r i c h b i o l o g i c a l res o u r c e s . T h e r e i n d e e r a n d s e a m a m m a l s a r e no l o n g e r i m p o r t a n t on a g l o b a l scale, b u t t h e y cont i n u e to be of g r e a t i n t e r e s t to t h e i n d i g e n o u s p e o p l e s . T h e fish r e s o u r c e s of t h e B a r e n t s a n d Bering seas and the Greenland waters are a m o n g t h e g r e a t e s t in t h e world. A n y p e t r o l e u m a c t i v i t y u p t h e r e is g o i n g to l a s t for p e r h a p s a c e n t u r y or two. F o r t h e p e o p l e s s e t t l e d on t h e n o r t h e r n coasts, t h e f i s h i n g i n d u s t r y will cont i n u e to b e a s o u r c e of living for ever. T h e o t h e r a r c t i c m i n e r a l r e s o u r c e s a r e pres e n t l y m o s t l y e x p l o i t e d in t h e S o v i e t Arctic. I n t h e K o l a P e n i n s u l a a n d S i b e r i a , nickel, cobalt, p l a t i n u m , c o p p e r , gold, tin, a n d i r o n a r e prod u c e d on a l a r g e s c a l e in G r e e n l a n d , t h e u n i q u e c r y o l i t e m i n e is e x h a u s t e d ; o n l y a l e a d - z i n c m i n e is in o p e r a t i o n . T w o r i c h d e p o s i t s of t h e s a m e m e t a l s h a v e b e e n p u t into o p e r a t i o n in A r c t i c C a n a d a , also. M o r e will b e f o u n d a s e x p l o r a t i o n g o e s on.
Indigenous People T h e social i m p a c t of p e t r o l e u m d e v e l o p m e n t on t h e i n d i g e n o u s p e o p l e of t h e A r c t i c will b e c o n s i d e r e d b y o t h e r s p e a k e r s . B u t to t h e b a s i c f e a t u r e s of t h e A r c t i c also b e l o n g s t h e v e r y e x i s t e n c e of t h e s e p e o p l e s , w h o h a v e lived a n d w o r k e d u n d e r h a r s h c o n d i t i o n s for t h o u s a n d s of y e a r s , a n d w h o h a v e b e c o m e p a r t of t h e ecos y s t e m . T h e y a r e t h e e s k i m o s a n d i n d i a n s of N o r t h A m e r i c a a n d G r e e n l a n d (110,000), t h e C h u k c h i s , S a m o y e d s , a n d o t h e r a r c t i c g r o u p s of S i b e r i a a n d N o r t h e r n R u s s i a (7-800,000). T h e s e f i g u r e s also i n c l u d e p e o p l e s living in n e a r b y s u b a r c t i c a r e a s , w h e r e t h e 30-40,000 l a p s of n o r t h e r n F e n n o - S c a n d i a also live. 31
Gaps in Knowledge I s h o u l d like to e n d t h i s e x p o s e of t h e b a s i c f e a t u r e s of t h e A r c t i c b y r e m i n d i n g y o u t h a t t h e r e a r e still l a r g e g a p s in o u r k n o w l e d g e . T h e u n d e r s t a n d i n g of t h e p r o c e s s e s a f f e c t i n g t h e s e a ice, its d i s t r i b u t i o n a n d d y n a m i c s is m o s t imp o r t a n t . F o r t h e e x p l o i t a t i o n of e n e r g y r e s o u r c e s in t h e Arctic, i n c l u d i n g t r a n s p o r t a t i o n to m a r -
32
k e t s a t h o r o u g h s t u d y of t h e e c o s y s t e m in t h e i c e - i n f e s t e d w a t e r s , in p a r t i c u l a r its m a r g i n a l zones, is a n o t h e r m u s t . We h a v e s o m e g e n e r e a l i n f o r m a t i o n on t h e p h y s i c a l a n d b i o l o g i c a l featur e s of t h e Arctic, b u t w e o f t e n l a c k p r e c i s e d a t a on c r i t i c a l a r e a s , a s w e l l as i n f o r m a t i o n a b o u t t h e e x t r e m e c o n d i t i o n s , n e e d e d b o t h for industrial standards and governmental monitoring and regulation.
Basic Features of the Arctic Tore Gjelsvik Norwegian Polar Research Institute, Oslo
Abstract
Introduction
77~e basic f e a t u r e s of the Arctic are caused in parr by the g e o m a g n e t i c relationships, in part by the i n c l i n a t i o n of the axis of the earth in relation to its orbit, as well as by the physiographic and topographic conditions.
W h a t is t h e A r c t i c ? B e i n g a s k e d t h i s q u e s t i o n , most people think about the area around the N o r t h Pole as a r e g i o n w i t h c o m p l e t e w i n t e r d a r k n e s s or m i d n i g h t sun, p o l a r b e a r s a n d r e i n deer, e s k i m o s , t u n d r a a n d p e r m a f r o s t , a n d a cold a n d h a r s h c l i m a t e - - g e n e r a l l y , s o m e t h i n g i n h o s p i t a b l e a n d u n p l e a s a n t . T h o s e of u s w h o k n o w t h e A r c t i c feel d i f f e r e n t a l t h o u g h a t t i m e s w e a d m i t it c a n b e r o u g h up t h e r e . To u s t h e A r c t i c is a n a r e a of u n b e l i e v a b l e b e a u t y a n d solitude, of d r e a m s a n d c h a l l e n g e .
To start f r o m the very top: the g e o m a g n e t i c condition allows interaction b e t w e e n solar plasma and the u p p e r atmosphere, causing m a g n e t i c storms and aurora which disturb magnetic m e a s u r e m e n t s and the propagation of the radio waves. This gives n a v i g a t i o n and c o m m u n i c a t i o n difficulties. However, it also m a k e s the Arctic a m o s t i m p o r t a n t scientific u'indow to the outer space. The geography of the Arctic can be described as a centrally located ocean, surrounded by low land and a f e w high m o u n t a i n ranges and narrow straits leading to the world oceans. In this way it differs f u n d a m e n t a l l y f r o m the Antarctic, which is a c o n t i n e n t surrounded by a big ocean. The Arctic climate, although polar, is less severe than the A n t a r c t i c one. The f e a t u r e s of the Arctic, w h i c h give m o s t problems to the a c t i v i t i e s of man, are of two types: the p e r m a n e n t p a c k ice f i l l i n g up the Arctic Basin and e x p a n d i n g into a d j a c e n t seas during winter, the p e r m a f r o s t and particularly the t h a w i n g during the s u m m e r of the 1--2 m thick u p p e r m o s t layers of the soil. In addition to the description of the geophysical characteristics of the various A r c t i c regions or zones m e n t i o n is made of biologic features, the i n d i g e n o u s people and of e n v i r o n m e n t a l matters. 0165-232X/83/$03.00
FIGURE 1.
© 1 9 8 3 Elsevier Science Publishers B.V.
27
These are the feelings, what are the realities? In o r d e r to d e s c r i b e t h e m , o n e h a s to d e f i n e t h e b o r d e r s of t h e Arctic. S o m e p e o p l e u s e t h e latit u d e s s u c h as t h e A r c t i c circle or t h e 60's d e g r e e N. In t h e U.S. o r C a n a d a t h e l a t t e r is o f t e n used, w h i c h m e a n s t h a t e v e n m o s t of s o u t h e r n N o r w a y is i n c l u d e d . A n y o n e h a v i n g s w e a t e d through the tropical temperatures during last s u m m e r h e r e in Oslo, will h a v e d i f f i c u l t i e s in accepting that definition. There are other a l t e r n a t i v e s s u c h as t h e n o r t h e r n t r e e line or t h e l i m i t of c o n t i n e o u s p e r m a f r o s t in t h e lowlands. N o n e of t h e s e g i v e s u s a b o r d e r l i n e in t h e sea. I p r e f e r to u s e t h e + 10°C i s o t h e r m for t h e w a r m e s t m o n t h , July, w h i c h c o i n c i d e s r e l a t i v e l y well w i t h t h e t r e e line, a n d w h i c h is s h o w n in Fig. 1. A c c o r d i n g to t h i s d e f i n i t i o n , t h e A r c t i c c o m p r i s e s 14 mill. s q u a r e k m s of s e a a n d 8 of land.
Cosmic Geophysics In d e s c r i b i n g t h e b a s i c f e a t u r e s of t h e Arctic, I w o u l d l i k e to s t a r t f r o m t h e v e r y top, t h e u p p e r a t m o s p h e r e a n d t h e n e a r - e a r t h s p a c e in p o l a r r e g i o n s . Fig. 2 s h o w s a s k e t c h of t h e e a r t h ' s m a g n e t i c field e n v e l o p e a n d of t h e f l o w l i n e s of t h e s o l a r wind. T h e e n e r g e t i c p a r t i c l e s of t h e s o l a r w i n d a r e p i c k e d u p b y t h e m a g n e t i c field l i n e s a n d d i r e c t e d t o w a r d s t h e p o l a r caps, w h e r e t h e y i n t e r a c t w i t h a t o m s of t h e u p p e r a t m o s p h e r e to p r o d u c e t h e b e a u t i f u l p o l a r lights, or
w,~
FIGURE 2.
28
S k e t c h of the Earth's m a g n e t i c - f i e l d envelope, or m a g n e t o s p h e r e , and its c o n n e c t i o n to the p o l a r regions (not to scale). R e l e v a n t p l a s m a regions a n d s a m p l e m a g n e t i c f i e l d lines c o n n e c t i n g the p o l a r cap to the i n t e r p l a n e t a r y f i e l d are shown.
aurora, but at the same time disturb the m a g n e t i c field a n d r a d i o e m i s s i o n s . B e f o r e t h e satellites were introduced, telecommunication a n d n a v i g a t i o n in t h e h i g h a r c t i c w e r e r a t h e r difficult. N o r t h of a p p r o x i m a t e l y 78 d e g r e e s N, s a t e l l i t e t e l e c o m m u n i c a t i o n is still n o t p o s s i b l e . A t t h e s a m e t i m e , t h e s e e f f e c t s h a v e m a d e it p o s s i b l e f o r c o s m i c p h y s i c i s t s a n d s p a c e scientists to o b s e r v e d i r e c t l y m a n i f e s t a t i o n s of p h e n o m e n a o c c u r r i n g in t h e d e e p s p a c e . T h e p o l a r a r e a s h a v e t h u s b e c o m e t h e E a r t h ' s w i n d o w for r e m o t e s e n s i n g a n d o t h e r s t u d i e s of t h e s p a c e a n d its e f f e c t s on o u r e n v i r o n m e n t .
Physiography T h e A r c t i c m a y b r i e f l y be d e s c r i b e d a s a pere n n i a l l y ice-covered, d e e p ocean, s u r r o u n d e d b y i s l a n d s , c o n t i n e n t a l c o a s t a l a r e a s , a n d of peripheral , seasonally ice-covered seas. The landm a s s e s m o s t l y c o n s i s t of l o w l a n d . H i g h m o u n t a i n r a n g e s a r e f o u n d o n l y in A l a s k a , e a s t e r n m o s t S i b e r i a a n d C a n a d a , a n d in G r e e n l a n d . T h e b o t t o m of t h e p e r i p h e r a l s e a s c o n s i s t s l a r g e l y of e x t e n s i v e a n d s h a l l o w c o n t i n e n t a l shelves. T h e t h r e e to five t h o u s a n d m d e e p p o l a r b a s i n h a s a r a t h e r c o m p l i c a t e d m o r p h o l o g y . It is i n t e r s e c t e d b y two m a j o r s u b s e a m o u n t a i n r i d g e s called the Alpha-Mendeleyev-Ridge and the L o m o n o s o v Ridge, t h e l a t t e r c r o s s i n g n e a r t h e N o r t h Pole w i t h a c r e s t of 1000 to 1500 m b e l o w s u r f a c e . A m e d i a n rift v a l l e y s p l i t s t h e b a s i n on t h e E u r a s i a n side of t h e L o m o n o s o v R i d g e in two s u b - b a s i n s . T h e 500 k m w i d e a n d 2500 m deep F r a m S t r a i t b e t w e e n G r e e n l a n d a n d Svalb a r d p r o v i d e s t h e m o s t i m p o r t a n t c h a n n e l for e x c h a n g e of w a t e r b e t w e e n t h e p o l a r b a s i n a n d the world oceans. The Polar Ocean constantly receives fresh water from the big north-flowing Siberian and Canadian rivers, giving a brackish s u r f a c e l a y e r t h a t e n h a n c e s t h e f o r m a t i o n of ice. A l o n g t h e e a s t side of t h e F r a m S t r a i t w a r m a t l a n t i c w a t e r e n t e r s t h e p o l a r b a s i n . To b a l a n c e these inputs, the excess water and large masses of p o l a r p a c k i c e flow s o u t h a l o n g t h e o p p o s i t e side of t h e s t r a i t .
Geology O n l y a c c e s s i b l e p a r t s of t h e A r c t i c c o n t i n e n t a l s h e l v e s a n d t h e floor of s o m e p e r i p e h e r a l s e a s h a v e b e e n s u b j e c t e d to s y s t e m a t i c g e o l o g i c a l s u r v e y s up to now. In t h o s e p a r t s t h e b a s e m e n t is c o v e r e d b y f r o m 2 to m o r e t h a n 10 k m of sedi-
ments, with a substantial hydrocarbon potential in s o m e areas. T h i s a s p e c t will be t r e a t e d b y later speakers. From the central, perennially ice-covered b a s i n the d a t a are few, u n e v e n l y dist r i b u t e d a n d p r e l i m i n a r y . W h a t w e know, is based u p o n m e a s u r e m e n t s f r o m Soviet, U.S. a n d c a n a d i a n scientific s t a t i o n s of f l o a t i n g ice a n d from airborne geophysical surveys. In general the b a s e m e n t of t h e Arctic sea floor s e e m s to be covered by s e d i m e n t a r y s e q u e n c e s of 2 k m t h i c k n e s s , w h i c h is m o r e t h a n i n a n y o t h e r o c e a n b a s i n . I n s o m e places, e v e n 5 k m or m o r e of s e d i m e n t s h a v e b e e n i n f e r r e d . I n t h e C a n a d a basin the layers thicken seawards, and s t r u c t u r a l t r a p s h a v e b e e n o b s e r v e d . T h e Lomon o s o v R i d g e is b y m o s t s c i e n t i s t s c o n s i d e r e d a f r a g m e n t of t h e E u r a s i a n c o n t i n e n t a l shelf. T h e o r i g i n of t h e A l p h a - M e n d e l e y e v - R i d g e is m o r e q u e s t i o n a b l e . A l t h o u g h s o m e s c i e n t i s t s are i n f a v o u r of a c o n t i n e n t a l crust, it m u s t be s t u d i e d in m o r e d e t a i l b e f o r e safe c o n c l u s i o n s c a n be drawn.
Biology Biological c o n d i t i o n s in t h e Arctic a r e c h a r a c t e r i z e d by low p r i m a r y p r o d u c t i o n ( a l t h o u g h in s o m e arctic a n d s u b - a r c t i c seas it c a n be high), a n d e c o s y s t e m s w i t h few species a n d populat i o n s r a n g i n g f r o m few to v e r y a b u n d a n t . T h e y often show r e m a r k a b l e b e h a v i o r a l a d a p t a t i o n s , high v u l n e r a b i l i t y to c h a n g e , a n d slow r e c o v e r y if locally d i s r u p t e d , b u t a r e t o u g h over t h e Arctic as a whole.
Climate T h e p o p u l a r c o n c e p t of t h e Arctic as a r e g i o n of p e r p e t u a l b i t t e r cold a n d deep s n o w is r a t h e r incorrect. T h e e x t r e m e t e m p e r a t u r e s a n d snowfalls are f o u n d i n t h e arctic b o r d e r l a n d s or e v e n in the s u b - a r c t i c areas. T h e m e a n air t e m p e r a t u r e over the Arctic b a s i n d u r i n g w i n t e r is - 3 0 to - 35 ~C, the lowest r e a d i n g s a r o u n d - 50°C. I n the s u m m e r , s u r f a c e air t e m p e r a t u r e s are n e a r the f r e e z i n g p o i n t a n d m a y go u p to a few d e g r e e s a v b o v e it (Fig. 3). A n n u a l p r e c i p i t a t i o n is v e r y low, 100 to 150 m m , m o s t of it f a l l i n g in t h e s u m m e r or a u t u m n . Low clouds a n d fog are a c o m m o n nuisance, especially during the summ e r s e a s o n . W i n d s are m o d e r a t e to low. T h e c l i m a t e of t h e Arctic as a w h o l e is d e p e n d e n t o n a n u m b e r of factors, s u c h as: t h e lati-
FIGURE 3.
t u d e s d e t e r m i n i n g solar a l t i t u d e a n d t h e l e n g t h of the day; the p r o p o r t i o n of l a n d a n d sea a n d of ice-covered a n d o p e n w a t e r s ; t h e d i s t r i b u t i o n a n d t e m p e r a t u r e s of o c e a n c u r r e n t s ; t h e proportion of s n o w - c o v e r e d a n d b a r r e n s u r f a c e s o n l a n d as well as of the a r e a l e x t e n s i o n of the s e a 29
ice; t h e t o p o g r a p h y of t h e l a n d a r e a s . C l o s e l y r e l a t e d to m o s t of t h e s e f a c t o r s a r e t h e freq u e n c y , i n t e n s i t y a n d t r a c k s of t h e c y c l o n e s . T h e i n t e r a c t i o n of all t h e s e f a c t o r s g i v e s r i s e to a v a r i e t y of c l i m a t e r e g i m e s in t h e p e r i p h e r a l a r c t i c r e g i o n s . L a r g e p a r t s of G r e e n l a n d h a v e t e m p e r a t u r e s a b o u t 10°colder t h a n t h e c e n t r a l Arctic, b o t h in t h e s u m m e r a n d w i n t e r , p r i m a r i ly b e c a u s e of t h e h e i g h t of t h e ice cap. A n n u a l p r e c i p i t a t i o n is v e r y low e x c e p t for t h e s o u t h e r n a n d w e s t e r n p a r t s , w h e r e it is a r o u n d 500 m m . South-western Greenland has a moister and m i l d e r c l i m a t e , m o d e r a t e d b y t h e n e a r b y icef r e e o c e a n . T h e c o a s t a l a r e a s of n o r t h A m e r i c a a n d E u r a s i a h a v e c o n t i n e n t a l c l i m a t e , i.e. d r y a n d cold w i n t e r s a n d m i l d s u m m e r s . D u r i n g s u m m e r t h e g r e a t t e m p e r a t u r e c o n t r a s t bet w e e n t h e cold A r c t i c O c e a n a n d t h e w a r m i n t e r ior l a n d m a s s e s g i v e s v a r i a b l e w e a t h e r w i t h average temperatures around +10°C, but hotter s p e l l s m a y occur. P r e c i p i t a t i o n is r a t h e r low, m o s t l y b e t w e e n 100 a n d 250 m m . The Svalbard area experiences rather special w e a t h e r : T h a n k s to t h e n o r t h - t r e n d i n g , w a r m o c e a n c u r r e n t a n d t h e c y c l o n i c a c t i v i t y in t h e N o r w e g i a n a n d B a r e n t s seas, m u c h h i g h e r t e m p e r a t u r e s o c c u r d u r i n g w i n t e r t h a n s h o u l d be e x p e c t e d at t h e s e h i g h l a t i t u d e s . O p e n w a t e r t h e r e f o r e e x i s t s o u t s i d e t h e w e s t c o a s t of S p i t s b e r g e n up to a b o u t 80 d e g r e e s N all y e a r r o u n d . A v e r a g e w i n t e r t e m p e r a t u r e s on t h e w e s t c o a s t of S p i t s b e r g e n , a t 78 d e g r e e s N, is a b o u t 15°C w a r m e r t h a n a t C a p e C h e l y u s k i n a t t h e s a m e lat i t u d e in S i b e r i a . In t h e w i n t e r a n d s p r i n g , h i g h p r e s s u r e a r e a s w i t h cold a r c t i c a i r m a s s e s m a y f r e q u e n t l y d o m i n a t e t h e w e a t h e r s i t u a t i o n in S v a l b a r d . Thus, g r e a t t e m p e r a t u r e v a r i a t i o n s a r e t y p i c a l , too, a n d e v e n a t h i g h a l t i t u d e s r a i n c a n fall in w i n t e r t i m e . P r e c i p i t a t i o n is h i g h e r t h a n in m o s t o t h e r a r c t i c a r e a s , e s p e c i a l l y on g l a c i e r s l o p e s on t h e e a s t side, w h e r e it m a y r e a c h 1000 m m a n n u a l l y . T h e s t r o n g e s t w i n d s in t h e A r c t i c o c c u r in s o u t h G r e e n l a n d a n d in t h e N o r w e g i a n a n d B a r e n t s seas.
Ice T h e f o r m a t i o n of ice a t s e a a n d on l a n d a r e t h e m o s t i m p o r t a n t c l i m a t i c e f f e c t s for t h e dev e l o p m e n t of a r c t i c e n e r g y r e s o u r c e s . T h e s e a ice c o v e r s on t h e a v e r a g e a m i n i m u m of 5.2 m i l l s q u a r e k m in S e p t e m b e r a n d a m a x i m u m of 11.7 mill s q u a r e k m in M a r c h - A p r i l (Fig. 4). O n l y a s m a l l p a r t is s m o o t h f a s t ice, up to a c o u p l e of m t h i c k n e s s f o r m e d in t h e w i n t e r in n e a r - s h o r e 30
FIGURE 4. . . . . Average minimum extent of sea ice ......... Average maximum extent of sea ice a r e a s , a n d l a r g e l y m e l t i n g in t h e s u m m e r time. M o s t of it is m o v i n g ice - - p a c k i c e - - w i t h a t h i c k n e s s of 2 to 6 m d e p e n d i n g u p o n a g e a n d location. D u e to w i n d p r e s s u r e , tide a n d o c e a n curr e n t s t h i s ice is in c o n s t a n t m o t i o n , f o r m i n g h i g h p r e s s u r e r i d g e s of ice r u b b l e , a n d o p e n l e a d s in a c o n f u s i n g p a t t e r n . V a r i a t i o n s in size a n d a g e of t h e ice floes c a n be c o n s i d e r a b l e within short distances. Pressure ridges are m o s t l y 1-2 m high, m a x . 15 m, a n d m a y e x t e n d to a d e p t h of 50 m u n d e r t h e s u r f a c e . In t h e B e a u f o r t S e a t h e p a c k i c e m o v e s in a g r e a t g y r e w i t h low s p e e d s in t h e c e n t r e , a n d increasing outwards. In the Eurasian basin, the ice g e n e r a l l y m o v e s w i t h a n a v e r a g e s p e e d of 3 cm/sec from the siberian Shelf towards the F r a m S t r a i t w h e r e t h e s p e e d a c c e l e r a t e s to 10-15 c m / s e c . A l o n g t h e b o r d e r s , s m a l l e r g y r e s a r e f o r m e d . T h e w i n t e r ice is h a r d a n d tough, in the summer the surface gets slushy and puddled, making surface transport and airplane l a n d i n g difficult a n d h a z a r d o u s . In m o s t of t h e a r c t i c h i g h l a n d s , g l a c i e r s a r e u b i q u i t o u s , t h e G r e e n l a n d ice c a p b e i n g b y f a r t h e m o s t i m p o r t a n t , c o v e r i n g a n a r e a of 1.7 mill s q u a r e k m w i t h u p to m o r e t h a n 3 k m d e p t h . G l a c i e r s u r g e s of h i g h s p e e d , up to 35 m p e r d a y ,
a r e n o t u n c o m m o n in a r c t i c m o u n t a i n o u s a r e a s . G r e a t e r d a n g e r to h u m a n a c t i v i t y s t e m s f r o m i c e b e r g s c a l v i n g f r o m f i o r d g l a c i e r s , ice c a p s a n d ice s h e l v e s . T h e l a r g e s t a r e t h e r a r e t a b u l a r iceb e r g s w h i c h m a y b e u p to 30 k m w i d e a n d 60 m thick, b u t also t h e i r r e g u l a r i c e b e r g s c a n b e large a n d h a v e e v e n d e e p e r d r a f t s , up to 450 m. M o s t of t h e m a r e f r o m G r e e n l a n d a n d E l l e s m e re L a n d . Q u i t e a few a r e c a r r i e d s o u t h w a r d s into t h e s h i p p i n g l a n e s of t h e N o r t h A t l a n t i c b y t h e s w i f t e a s t G r e e n l a n d c u r r e n t or a l o n g t h e c o a s t of L a b r a d o r . F u t u r e p e t r o l e u m a c t i v i t y on t h e e a s t G r e e n l a n d c o n t i n e n t a l s h e l f will no d o u b t be g r e a t l y d i s t u r b e d b y t h e m , b u t i c e b e r g s on t h e e a s t side of t h e S v a l b a r d a r c h i p e l a g o s h o u l d not be d i s r e g a r d e d , e i t h e r .
Permafrost Perennially frozen ground -- permafrost -occurs where the ground temperature remains c o n s t a n t l y b e l o w 0°C o v e r a p e r i o d of y e a r s . Its d e p t h d e p e n d s on t h e a v e r a g e a n n u a l t e m p e r a ture, t h e t o p o g r a p h y a n d t h e l e n g t h of t i m e of t h e n e g a t i v e t e m p e r a t u r e b a l a n c e . O r d i n a r i l y , it is a b s e n t u n d e r g l a c i e r s a n d sea, a l t h o u g h it m a y b e p r e s e n t u n d e r s h a l l o w a n d cold seas, possibly as a relic from the time when the sea level w a s l o w e r t h a n t o d a y . T h e t h i c k e s t p e r m a f r o s t - - 1500 m - - is r e c o r d e d in S i b e r i a . F r o m C a n a d a 600 m is r e p o r t e d . I n c e n t r a l S p i t s b e r g e n , 3-400 m is f o u n d u n d e r t h e m o u n t a i n s , 100-200 m u n d e r t h e v a l l e y s . Ice is c o n c e n t r a t e d in t h e p o r e s of u n c o n s o l i d a t e d s e d i m e n t s , b u t also in w e d g e s a n d s h e e t s ( g r o u n d ice). D u r i n g s u m m e r t h e s u r f a c e l a y e r s will m e l t to a d e p t h of 1-2 m, m a x i m u m 5. T h i s s o - c a l l e d a c t i v e l a y e r is b i o l o g i c a l l y v e r y i m p o r t a n t , s i n c e it s u p p o r t s a s p a r s e v e g e t a t i o n . D u e to t h e i m p e r m e a b i l i t y of t h e p e r m a f r o s t below, t h e s u r f a c e l a y e r g e t s v e r y w e t a n d r e p r e s e n t s a s e r i o u s p r o b l e m for g r o u n d t r a n s p o r t a t i o n a n d c o n s t r u c t i o n w o r k in t h e Arctic. T h e a l t e r n a t i o n of t h a w i n g a n d freezing p r o d u c e s v e r y s t r i k i n g s t r u c t u r e s in a r c t i c soils, c a l l e d p a t t e r n e d g r o u n d . T h e m a t e r i a l is o f t e n s o r t e d a c c o r d i n g to size, s t o n e s a r e c o n c e n t r a t e d a n d o r i e n t e d in p o l y g o n s or rings, s o m e e e n t i m e t r e s to t e n t h of m e t r e s a c r o s s , w i t h t h e f i n e r m a t e r i a l in t h e m i d d l e . O n s l o p i n g hills, t h e w h o l e a c t i v e l a y e r s l i d e s b y g r a v i t y (solifluction), a n d t h e p a t t e r n e d s t r u c t u r e s a r e d r a w n o u t to p a r a l l e l s t r i p e s or b a n d s . T h e f r e q u e n t f r e e z i n g a n d t h a w i n g l e a d to a n e x t e n sive f r a c t u r i n g of t h e s u r f a c e s of e x p o s e d r o c k s .
Thus, in t h e Arctic, m e c h a n i c a l d i s i n t e g r a t i o n g r e a t l y o u t w e i g h s c h e m i c a l p r o c e s s e s in t h e w e a t h e r i n g of r o c k s . In c o m b i n a t i o n w i t h s l u s h flow, s o l i f l u c t u i o n , r i v e r a n d g l a c i a l e r o s i o n t h i s r e s u l t s in a r a p i d d e n u d a t i o n of m o u n t a i n s . T h e v e r y m u d d y r i v e r s d e p o s i t t h e i r l o a d in l o w e r valleys, deltas and other near-shore areas. Tides, c u r r e n t s a n d ice s c o u r r a p i d l y a l t e r s t h e c o n f i g u r a t i o n of c o a s t l i n e s .
Other resources T h i s c o n f e r e n c e is f o c u s e d u p o n t h e A r c t i c e n e r g y r e s o u r c e s . H o w e v e r , it s h o u l d n o t be forgot t h a t t h e A r c t i c also c o n t a i n s o t h e r i m p o r t a n t m i n e r a l r e s o u r c e s , as w e l l as r i c h b i o l o g i c a l res o u r c e s . T h e r e i n d e e r a n d s e a m a m m a l s a r e no l o n g e r i m p o r t a n t on a g l o b a l scale, b u t t h e y cont i n u e to be of g r e a t i n t e r e s t to t h e i n d i g e n o u s p e o p l e s . T h e fish r e s o u r c e s of t h e B a r e n t s a n d Bering seas and the Greenland waters are a m o n g t h e g r e a t e s t in t h e world. A n y p e t r o l e u m a c t i v i t y u p t h e r e is g o i n g to l a s t for p e r h a p s a c e n t u r y or two. F o r t h e p e o p l e s s e t t l e d on t h e n o r t h e r n coasts, t h e f i s h i n g i n d u s t r y will cont i n u e to b e a s o u r c e of living for ever. T h e o t h e r a r c t i c m i n e r a l r e s o u r c e s a r e pres e n t l y m o s t l y e x p l o i t e d in t h e S o v i e t Arctic. I n t h e K o l a P e n i n s u l a a n d S i b e r i a , nickel, cobalt, p l a t i n u m , c o p p e r , gold, tin, a n d i r o n a r e prod u c e d on a l a r g e s c a l e in G r e e n l a n d , t h e u n i q u e c r y o l i t e m i n e is e x h a u s t e d ; o n l y a l e a d - z i n c m i n e is in o p e r a t i o n . T w o r i c h d e p o s i t s of t h e s a m e m e t a l s h a v e b e e n p u t into o p e r a t i o n in A r c t i c C a n a d a , also. M o r e will b e f o u n d a s e x p l o r a t i o n g o e s on.
Indigenous People T h e social i m p a c t of p e t r o l e u m d e v e l o p m e n t on t h e i n d i g e n o u s p e o p l e of t h e A r c t i c will b e c o n s i d e r e d b y o t h e r s p e a k e r s . B u t to t h e b a s i c f e a t u r e s of t h e A r c t i c also b e l o n g s t h e v e r y e x i s t e n c e of t h e s e p e o p l e s , w h o h a v e lived a n d w o r k e d u n d e r h a r s h c o n d i t i o n s for t h o u s a n d s of y e a r s , a n d w h o h a v e b e c o m e p a r t of t h e ecos y s t e m . T h e y a r e t h e e s k i m o s a n d i n d i a n s of N o r t h A m e r i c a a n d G r e e n l a n d (110,000), t h e C h u k c h i s , S a m o y e d s , a n d o t h e r a r c t i c g r o u p s of S i b e r i a a n d N o r t h e r n R u s s i a (7-800,000). T h e s e f i g u r e s also i n c l u d e p e o p l e s living in n e a r b y s u b a r c t i c a r e a s , w h e r e t h e 30-40,000 l a p s of n o r t h e r n F e n n o - S c a n d i a also live. 31
Gaps in Knowledge I s h o u l d like to e n d t h i s e x p o s e of t h e b a s i c f e a t u r e s of t h e A r c t i c b y r e m i n d i n g y o u t h a t t h e r e a r e still l a r g e g a p s in o u r k n o w l e d g e . T h e u n d e r s t a n d i n g of t h e p r o c e s s e s a f f e c t i n g t h e s e a ice, its d i s t r i b u t i o n a n d d y n a m i c s is m o s t imp o r t a n t . F o r t h e e x p l o i t a t i o n of e n e r g y r e s o u r c e s in t h e Arctic, i n c l u d i n g t r a n s p o r t a t i o n to m a r -
32
k e t s a t h o r o u g h s t u d y of t h e e c o s y s t e m in t h e i c e - i n f e s t e d w a t e r s , in p a r t i c u l a r its m a r g i n a l zones, is a n o t h e r m u s t . We h a v e s o m e g e n e r e a l i n f o r m a t i o n on t h e p h y s i c a l a n d b i o l o g i c a l featur e s of t h e Arctic, b u t w e o f t e n l a c k p r e c i s e d a t a on c r i t i c a l a r e a s , a s w e l l as i n f o r m a t i o n a b o u t t h e e x t r e m e c o n d i t i o n s , n e e d e d b o t h for industrial standards and governmental monitoring and regulation.