DK - Water Cycles: The source of life from start to finish

The source of life from start t o nish

Authors and co nsultants: Lead consultant Derek Harvey Plants and Animals authors Steve Setford, Anita Ganeri, and Lizzie Munsey Prehistory author and c onsultant Emily Keeble Biology author Emily Dodd Space author and c onsultant Sophie Allan Tec hnology and humans author and consultant Clive Giord Earth consultant Anthea Lacchia Earth and W eat her authors Anita Ganeri, Steve Setford, John F ar ndon, and Lizzie Munsey Weat her consultant John Fa rndon Illustrated by Sam Fa lconer Senior editor Carrie Love Designer Charlotte Milner US Editor Jane Perlmutter US Senior editor Shannon Beatty Additional editing Marie Greenwood, Jolyon Godda rd Additional designing Rachael Hare, Robert Perry , Karen Hood, and Claire P atane DTP designer Sachin Gupta Picture re searchers Rituraj Singh and Vag isha Pushp Managing editor Penny Smith Managing art editor Mabel Chan Pre-pro ducer Robert Dunn Producer John Casey Publishing director Sarah Larter First American Edition, 2021 Published in the United States by DK Publishing 1450 Broadway , S uite 801, New Yor k, New Y or k 10018 Copyright 2021 Dorling Kindersley Limited DK, a Division of Pe nguin Random House LLC 21 22 23 24 25 10 9 8 7 6 5 4 3 2 1 001321055July/2021 All rights reserved. Without limiting the rights under the copyright r eserved above, no part of this publication may be r eprodu ced, st ored in or intr oduced into a retrieval sy stem, or transmitted, in any f orm, or by an y means (electronic, mechanic al, ph otocopying, record ing, or otherwise), without the prior written permission of the copyright owner . Published in Great Britain by Dorling Kinder sley Limited. A catalog re cord for this book is available fro m the Library of C ongress. ISBN: 978-0-7440-3334-2 DK books are available at special discounts when pur chased in bulk for sales promotions, prem iums, fund-r aising, or educa tional use. F or details, c ontact: DK Publishing Special Marke ts, 1450 Broadway , S uite 801, New Yor k, New Y or k 10018 SpecialSales@dk.com Printed and bound in China All images Dorling Kindersley Limited For further information see: www. dkimages.com For the curi ous www.dk.com This book was made with Fo rest Stewardship Co uncil cert ifi ed paper one small step in DK s commitment to a sustainable future. For more informati on go to www.dk .com/our-gr een-pledge

The source of life from start to nish

What is wa ter? Where is wa ter? Cycles and wate r Water o n Eart h The power of water Making and losing oceans Clouds Cloud ty pes Hurricane Snowf lake River Water fall Groundwat er Hot springs Cave Vol canic island Glacier Ocean-sur face currents Usin g water Water in cells Water in plants Food from wa ter Water i n humans Surviv ing dehy drat ion Collecti ng wate r Feeling thirs ty Deep-oc ean curren ts Ocean wav es Changing coastlines Tides Deep-sea vent

Water a nd humans Depending on wat er Hydrop ower Irrigati on Water i n the home Wast ewater Water in a sky scraper Water in space Glossary Index 144 Acknowl edgments Newt Frog Zooxanthell ae 120 Ke lp Life in water Surviv ing in water Ocean enviro nments Life in wa ter Jellyf ish Fluke Periwinkl e Water flea Crab Mayf ly Starf ish Manatee Orca Elephant seal Murrelet Shark Eel Te tra Clown fi sh Anglerf ish Ichthyo saur Sea snake

Scientis ts giv e water the spec ial code n ame of HO, to show ho w its molecules are mad e up. If thi s pond froze solid, the animals and plan ts in it would die. With no color , taste, or smell, water may seem a litt le boring. Bu t, i t is actually an amazing natural subs tance that m akes ou r planet special. Without water , there woul d be no life on Eart h. Most water on Eart h is liquid. Ho wever , at 2 F ( C) it becomes an invisible ga s called wat er vapor , and below 3 F (0 C) it turns to soli d ice. The smallest pie ces of wat er are calle d molecules. At tract ing (pulling) f orces between w ater molecu les make the molecules s tick t ogether to fo rm puddles, lakes, and oceans, while stil l allowing the water to f low easily . Water molecules are also attr acted t o many other materials. This mak es wa ter great at disso lving things it p ulls them apart so that they mix with the water . Whereve r water fl ows, thro ugh soil or thro ugh plants and anima ls, it carries dissolved mi nerals, nutrients, and other chemic als that are vita l for life. In addition to ma king life on Eart h possible, w ater molds t he land and coas ts through fal ling rai n, rushing rivers, slow-mov ing glaciers , and cra shing ocea n wav es. Life g iving and p lanet shaping water is truly amaz ing. Floating ice Ice floats on water because it is lighter . This is import ant fo r aquatic lif e. When ice f orms on the surfac e, it shields the water below from the cold air abov e, sto pping the rest of the waterand the things that live in itfr om freezing too. HH O

Surface tension pulls water into round dro plets. Some sm all, ligh t creatures can walk over ponds wit hout bre aking the water s s kin. Some mate rials, such as oil, repe l water . An oily coating on the fea thers o f waterbirds , such as t his gan net, keeps th e feath ers dry . The Grand Canyon is 6,00 ft (1 ,800 m) deep and 18 miles (29 km) wide . An unbrok en stre am of water t ravels up very t hin tubes inside plan ts. Water mole cules Wat er molecules are made up of tiny pieces of matte r called atoms. Eac h water molecule has two hy drog en atoms that join a single ox ygen ato m by f orce s called bonds. Surface skin When molecules at the surface of water pull on eac h other , they make t he water beha ve a s though it has a thin skin. This is called surfac e tension. Stic ky water The stickiness of water molecules is why wate r make s things wet. This stickiness also keeps the stre am of water rising up inside the stem of a plant. The water rises in continuous, unbro ken columns, fro m the roo ts to the leav eseve n when that plant is a tow ering tr ee. Shaping the land Wat er can bre ak up rock s into particles and carr y th em aw ay . The Grand Canyo n in Arizona, US, was carved out b y the wate rs of the Colorado Riv er ov er millions of years.