1. Byw mewn cylchfa weithredol
The Physical World Y Byd Ffisegol 3 Living in an Active Zone
Byw mewn cylchfa weithredol
How can the risks associated with volcanic and earthquake zones be reduced?
Sut gellir lleihau ar yr peryglon sy’n gysylltiedig â chylchfaoedd folcanig a daeargryn?
2.1 How are volcanoes monitored and what does this tell us about their state?
2.1 Sut mae llosgfynyddoedd yn cael eu monitro a beth mae hyn yn dweud wrthym am eu cyflwr?

2. Synhwyro o bell
hydroleg
nwy
seismigedd
Dadffurfiant tir
Mesuriadau geoffisegol

3. Seismigedd Seismicity
Defnyddio rhwydwaith o seismomedrau i fesur cynnydd mewn daeargrynfeydd
Using a network of seismometers to measure the increase in earthquakes
Hydroleg Hydrology
The pattern of valleys can influence where lahars go. Automatic sensors can detect the passage of a lahar. Mae’r patrwm o ddyffrynoedd yn gallu dylanwadu ble mae lahar yn mynd. Defnyddir offer awtomatig.

4. Monitoring ground deformation Monitro dadffurfiant tir
Changes at the surface tell us about the sub-surface
Mae newidiadau ar y wyneb yn helpu i ni ddeall o dan y wyneb
Mesur pellteroedd gyda meidrydd pellter electronig
Measuring distances using an electronic distance meter
Defnyddio GPS i fesur uchder tir a lleoliadau o gwmpas llosgfynydd
Using a GPS to measure land height and locations around a volcano
Interferometric Synthetic Aperture Radar
Defnyddio radar i ddangos sut mae’r tir wedi symud
Using radar to show earth deformation
Defnyddio gwyromedr i fesur ongl llethrau
Using a tiltmeter to measure slope angles
around a volcano
Mesur nwyon i weld os oes newidiadau
Measuring the content of volcanic gases to see if there are changes

5. Science is getting better Mae gwyddoniaeth yn gwella
People feel safer with technological advances
Monitoring equipment that can foretell volcanic activity
They can measure
the escape of gas (sulphur dioxide – bad egg smell)
Small earthquakes which act as a warning
Swelling of the sides of the volcano also warns of things to come
Quakeproof construction techniques are becoming more advanced.
But so far we are no closer to being to time earthquakes accurately
Mae pobl yn teimlo’n saffach gyda gwelliannau technolegol
Mae offer monitro yn gallu rhagweld gweithgaredd folcanig.
Maent yn gallu mesur
- nwy yn gollwng (swlffwr deiocsid – oglau o wyau drwg!!)
- daeargrynfeydd bach sydd fel rhybudd
- ochrau’r llosgfynydd yn chwyddo
Mae dulliau adeiladu a gwrthsefyll daeargryn yn gwella
Ond nid ydym yn gallu rhagweld pryd fydd daeargryn yn digwydd

6. What To Do If a Volcano Erupts
BEFORE:
Learn about your community warning systems and emergency plans.
Be prepared for the hazards that can accompany volcanoes:
Make evacuation plans.
If you live in a known volcanic hazard area, plan a route out and have a backup route in mind.
Develop an emergency communication plan.
In case family members are separated from one another during a volcanic eruption (a real possibility during the day when adults are at work and children are at school), have a plan for getting back together.
Ask an out-of-state relative or friend to serve as the "family contact," because after a disaster, it's often easier to call long distance. Make sure everyone knows the name, address, and phone number of the contact person.
Have disaster supplies on hand:
* Flashlight and extra batteries
* First aid kit and manual
* Emergency food and water
* Non-electric can opener
* Essential medicines
* Dust mask
* Sturdy shoes
* Get a pair of goggles and a throw-away breathing mask for each member of the household in case of ashfall.

7. PREDICTION & PREPARATION RHAGWELD A DARPARU
PREDICTION RHAGWELD
Earthquakes are very hard to predict * Mae’n anodd rhagweld daeargrynfeydd
Scientists can search for clues: * Gall gwyddonwyr chwilio am gliwiau
changes in well water levels newidiadau yn lefel dŵr daear
gas emissions allyriadau nwyon
cracks appearing in rocks craciau’n ymddangos mewn creigiau
even strange animal behaviour!! ymddygiad od gan anifeiliaid
Computers can analyse data to forecast future earthquakes BUT they can’t be predicted accurately as they occur unexpectedly.
Gall cyfrifiaduron ddadansoddi dat er mwyn rhagweld daeargrynfeydd yn y dyfodol OND nid ydynt yn gallu fod yn fanwl achos eu bod yn digwydd heb rybudd

8. Viewing platform
Laser reflector
Levelling surveys
Tiltmeter and gravitometer
Animal behaviour
Existing fault line
Water level in wells
Radon gas counter
Magnetometer and resistometer
Creep meter and gravitometer
Strainmeter
Seismograph
Water table
Ways of monitoring which can help predict earthquakes
Dulliau monitro all fod o gymorth i ragweld daeargryn

9. PREPARATION DARPARU
Good planning and preparation can reduce the effects of tectonic hazards
EMERGENCY DRILLS are held to practise what to do in the event of an earthquake
INFORMATION on emergency procedures can be made available to the public (e.g. in school classes, pamphlets, newspapers), sheltering under a table or avoiding standing next to walls can save your life!
EMERGENCY PLANS can be drawn up by the local authorities and government and practised in order to reduce damage, death and injury
MONITORING helps predict when hazards are coming so people can be warned
Gall cynllunio a darparu leihau’r effeithiau o bryglon tectoneg
Cynhelir DRILIAU ARGYFWNG er mwyn ymarfer bethi’w wneud os ddigwydd daeargryn.
Gellir cyhoeddi GWYBODAETH ar beth i’w wneud (e.e. mewn ysgolion, pamffledi, papurau newydd), gallai cysgodi o dan bwrdd neu osgoi sefyll nesaf i wal achub eich bywyd!
Gall awdurdodau lleol a chenedlaethol greu CYNLLUNIAU ARGYFWNG er mwyn lleihau difrod, marwolaeth ac anafiadau.
Mae MONITRO yn helpu rhagweld pryd mae peryglon yn dod fel gellir rhybuddio pobl.

10. PREPARATION DARPARU
FAMILIES can organise supplies of food and water, dust masks, spare clothes, basic medical supplies, shelters, torches, batteries, mobile phones and other useful stuff
EMERGENCY SERVICES such as the Police, Fire Brigade and Ambulance service can be well prepared to deal with any hazard
EMERGENCY SUPPLIES of water and power can be organised in advance
BUILDING & ROAD DESIGNS can be planned for earth movements so they don’t collapse under the strain
e.g. New skyscrapers in earthquake zones can be built with a computer controlled counterweight, cross bracings and special foundations to reduce the impact of an earthquake
Gall TEULUOEDD drefnu cyflenwad o fwyd a dŵr, mygydau llwch, dillad sbar, cyflenwadau meddygol, cysgodfeydd, tortsys, bateris, ffonau symudol ac ati
Gallai GWASANAETHAU ARGYFWNG fel heddlu, brigad dân ac ambiwlans fod wedi paratoi yn dda er mwynd elio ag unrhyw berygl
Gellir CYNLLUNIO ADEILADAU A FFYRDD i wrthsefyll symudiadau daear fel nad ydynt yn dymchwel
e.e. mae adeiladau uchel gyda technegau arbennig.