gg 103 aloha and welcome to geology of the hawaiian islands nasir gazdar, phd, mph 1. course...

GG 103 Aloha and Welcome toGeology of the Hawaiian IslandsNasir Gazdar, PhD, MPH

1. Course Website://www2.hawaii.edu/~nasir2. Announcements, Lecture notes and Study Guide Files, Extra credit, Geology Events at//myuhportal.hawaii.edu at GG 103 Course Site3. Hawaii Atlas, Plate Tectonics,Geology Text, CDs, DVDs atThe Library Reserve GG 1034. Email for any help. Mahalo for excellence.

1st term exam 150 points

Midterm 150 points

3rd term 150 points

Final exam 400 points

Presentation 150 points

Total 1000 points

Extra credit – to be announced in the class - may be emailed

Grade

A 900+

B 800+

C 700+

D 600+

GG 103 Exams and Grading

• Geology is vital in human civilization

• Geology in Today’s World• Geology - The scientific study of the Earth

– Physical Geology is the study of Earth’s materials, changes of the surface and interior of the Earth, and the forces that cause those changes

• Practical Aspects of Geology– Natural resources – Geological hazards– Environmental protection– Sea level Rise, Climate Change, Global Warming

Geology and Other Sciences

Physics

•Geophysics

•Seismology

Chemistry

•Mineralogy

•Petrology

•Geochemistry

Biology

•Paleontology

•Paleoecology

Astronomy

•Planetary Geology

•Helioseismology

•Economic Geology

•Hydrology

•Engineering Geology

•Petroleum Geology

•Historical Geology

•Geomorphology

•Oceanography

•Structural Geology

•Volcanology

Natural ResourcesAll manufactured objects depend on Earth’s resourcesLocalized concentrations of useful geological resources are mined or extractedIf it can’t be grown, it must be minedMost resources are limited in quantity and non-renewable

Earth Science: The science of GeologyEarth System Science

• Geology is the science that pursues an understanding of planet Earth

• Physical Geology - examines the materials composing Earth and seeks to understand the Internal Processes that operate beneath, and External Processes upon its surface.

• Historical Geology - seeks an understanding of the origin of Earth and its development through time

What Do Geologists Do?• Seek to understand all processes that operate on and

inside the Earth and on the Hawaiian Islands• Study:

– Our planet’s long history and origin of Hawaiian islands and their place on the earth in the ocean

– Landforms: volcanoes, reefs, water bodies (ocean, rivers and groundwater), mountains, valleys, glaciers, dunes

– Hazardous processes such as earthquakes, volcanic eruptions, tsunamis, floods, and landslides

– Rocks, minerals, water, geothermal resources of the Hawaiian Islands

Geology Involves Study of:

• Earth Materials (rocks, minerals, soils)– formation, effects on health, as resource or waste

• Natural Hazards– Volcanoes and volcanic eruptions, earthquakes, tsunamis,

floods, landslides, rockfalls• minimize loss of life

• Natural Resources – Volcanoes, Reefs, Beaches, Geothermal energy

• Hydrologic Processes of surface/ground water– Water resources, pollution

• Geologic Process– Atmospheric, hydrologic, and lithospheric

Africa

North America

SouthAmerica

Europe

Asia

Australia

Antarctica

Hawaii

Pacific Ocean

Mahukona

Pacific Ocean

Hawaii

Pacific Ocean

Indian Ocean

AsiaNorth America

South America

Australia

AtlanticOcean

Oceanic crust is forced below the fracture because oceanic crust is denser than the one composing the fracture. Magma is created at the subduction wedge

Subduction crack on the Pacific Oceanic crust

Earthquakes

Magma ChamberHotspot

Origin of Planet Earth, Sun and Solar SystemThe Nebular Hypothesis claims that 5 billion years ago, for reasons unknown, a huge nebular cloud began to contract under its own gravitational influence. As it contracted it also had some rotational motion. The more it contracted the faster the cloud rotated, causing the nebular cloud to take on a disk shape. As the cloud collapsed, the temperature of the central mass continued to increase and most of the material was gravitationally pulled toward the center, producing the Sun. However, because of the rotational motion, some dust and gases remained orbiting the Sun, forming planets.

Nebular HypothesisExplains Origin ofSun’s Solar System 8 Planets, Moons, Comets, AsteroidsRocky PlanetsMercuryVenusEarthMarsGaseous PlanetsJupiterSaturnUranusNeptuneDwarf Planet Pluto

As these fragments began to condense and collide, they joined together into larger objects which eventually became the planets which continued to orbit the Sun

• Earth formed as a planet in the Sun’s Solar system from a nebula: 4,600,000,000 years ago, 4.6 billion years, 4,600 million years

• Life on Earth began: 3,800,000,000 years• Geology: Science of processes related to:

– Composition, structure, history and life of Earth– Processes on the earth, landforms and islands

• Geology of Hawaiian Islands:• Studies entire spectrum of Hawaiian Islands physical

environment, Birth and Life of the Isles • It is geology applied to:

• Islands origin, volcanic formation and life stages• Awareness of unique geologic environment• Understand the geologic processes on the islands

Origin and evolution of Earth• Origin of planet Earth 4,600,000,000 years before

present• Nebular hypothesis – Sun and Solar System• While this theory incorporates more basic physics,

there are several unsolved problems. For example, a majority of the angular momentum in the Solar System is held by the outer planets. For comparison, 99% of the Solar System's mass is in the Sun, but 99% of its angular momentum is in the planets. Another flaw is the mechanism from which the disk turns into individual planets

• Layered structure developed by chemical segregation early in the formation of Earth

Earth is Unique

• No other planet in the solar system currently has the right chemical and physical mix needed to support life

• No conclusive evidence of life existing elsewhere in the universe has yet been discovered as far as we know

A view of Earth Planetary System• Earth is a planet that is rocky and self-contained

– Earth System and Spheres

• Earth’s spheres • Hydrosphere – water, oceans, lakes, rivers• Atmosphere - air• Biosphere – life and environment, ecosystem• Lithosphere - Solid Earth• Pedosphere – soil

– Cryosphere – ice sheets, Antarctica, Greenland– Anthrosphere – Human built environment

Our Planet’s “Five Spheres” or Subsystems• The Atmosphere:

– Nitrogen, oxygen, argon, carbon dioxide, and water vapor

• The Hydrosphere:– Oceans, lakes, streams, underground water, snow, and ice

• The Biosphere: Ecosphere, Sphere of Life– All of Earth’s organisms, as well as any organic matter not

yet decomposed, Anthrosphere is Human Living Environment

• The Geosphere – Crust, Lithosphere, Mantle and Core– The solid Earth from core to surface crust-– Crust composed principally of rock, minerals, sediments,

ores and soils

– Soils are in Pedosphere

The science of Geology• Some historical notes about geology

• The nature of Earth has been a focus of study for centuries

• Catastrophism • Uniformitarianism and the birth of modern

geology

UniformitarianismThe Rock Cycle

Uniformitarianism

Continuity of Cause and Effect

• Apply Cause and Effect to Future - Prediction

• Apply Cause and Effect to Present - Technology

• Apply Cause and Effect to Past - Uniformitarianism

Uniformitarianism does not mean:

• Catastrophes never occur

• Physical Conditions on Earth never Change

• Earth has always been the same

• Physical processes always occur at the same rate or intensity

• Laws of Physics have always been the same

Uniformitarianism does mean:

Using our knowledge of physical laws, we can test:• Whether catastrophes have occurred • Whether physical conditions on earth have changed,

and if so, how (climate change, ice ages, warm periods, high or low sea level, etc.)

• Whether physical laws themselves have changed in time, or elsewhere in the universe.

Geologic time• Geologists are now able to assign fairly accurate

dates to events in Earth history

• Relative dating and the geologic time scale • Relative dating means that dates are placed in their

proper sequence or order without knowing their age in years

Geologic time

• The magnitude of geologic time • Involves vast times – millions or billions of years • An appreciation for the magnitude of geologic time

is important because many processes are very gradual

The nature of scientific inquiry

• Science assumes the natural world is consistent and predictable

• Goal of science is to discover patterns in nature and use the knowledge to make predictions

• Scientists collect “facts” through observation and measurements

The nature of scientific inquiry• How or why things happen are explained using a

• Hypothesis – a tentative (or untested) explanation • Theory – a well-tested and widely accepted view

that the scientific community agrees best explains certain observable facts

The nature of scientific inquiry• Scientific methods

• Scientific method involves gathering facts through observations and formulation of hypotheses and theories

• There is no fixed path that scientists follow that leads to scientific knowledge

Earth as a system• Earth is a dynamic planet with many interacting

parts or spheres

• Parts of the Earth system are linked

• Characterized by processes that • Vary on spatial scales from fractions of millimeter

to thousands of kilometers • Have time scales that range from milliseconds to

billions of years

Earth as a system• The Earth system is powered by the Sun that

drives external processes in the • Atmosphere• Hydrosphere• At Earth’s surface

Earth as a system• The Earth system is also powered by the Earth’s

interior, Internal Processes.• Heat remaining from the formation and heat that

is continuously generated by radioactive decay powers the internal processes that produce volcanoes, earthquakes, and mountains

The rock cycle: part of the Earth system• The loop that involves the processes by which one

rock changes to another

• Illustrates the various processes and paths as earth materials change both on the surface and inside the Earth

The face of Earth• Earth’s surface has two principal divisions

• Continents• Ocean basins

• Significant difference between the continents and ocean basins is their relative levels

The face of Earth• Continents

• Most prominent features are linear mountain belts • Shields

• Ocean basins• Ocean ridge system – the most prominent

topographic feature on Earth• Deep-ocean trenches

Early evolution of Earth• Origin of planet Earth

• Most researchers believe that Earth and the other planets formed at essentially the same time from the same primordial material as the Sun

• Nebular hypothesis

• Layered structure developed by chemical segregation early in the formation of Earth

Earth’s internal structure• Earth’s internal layers can be defined by

• Chemical composition• Physical properties

• Layers defined by composition• Lithosphere, Crust• Mantle• Core

Structure of the EarthThe Earth is made up of three main layers: The core is at the center of the Earth The outer core is a mobile semi-molten layer around the inner core The mantle is a solid, rigid layer around the outer core; the top of mantle gets internal heat.The outer-shell of the Earth is called the LITHOSPHERE - crust. it's the part we're on now

Dynamic Earth – Plate Tectonics• Theory of Plate Tectonics

• Involves understanding the workings of our dynamic planet

• Began in the early part of the twentieth century with a proposal called continental drift – the idea that continents moved about the face of the planet

• Seafloor Spreading

Dynamic Earth• The theory of plate tectonics

• Theory, called plate tectonics, has now emerged that provides geologists with the first comprehensive model of Earth’s internal workings

• Plate boundaries• All major interactions among individual plates

occurs along their boundaries

8 Major Tectonic Plates of the Lithosphere

Ring of Fire

Ring of Fire

Dynamic Earth• Plate boundaries

• Divergent boundary – two plates move apart, resulting in upwelling of material from the mantle to create new seafloor

• Convergent boundary – two plates move together with subduction of oceanic plates or collision of two continental plates

Dynamic Earth• Plate boundaries

• Transform boundaries - located where plates grind past each other without either generating new lithosphere or consuming old lithosphere

• Changing boundaries - new plate boundaries are created in response to changes in the forces acting on the lithosphere