Climate structured answers 25/9

3	(a)
		(i)	Identify the type of climate shown in Fig. 2.                                                            [1] ·       Monsoon climate (Not accept if there’s spelling mistakes)
		(ii)	Describe the characteristics of the climate identified in 3(a)(i).                              [4] ·       High mean annual temperatures [0.5] of 27 degree Celsius. [0.5] ·       The annual temperature range is small [0.5]  at 11 degree Celsius. [0.5] ·       High amount of total annual precipitation [0.5] of 1600mm between June and September [0.5]  . ·       Distinct wet and dry season [1] with more precipitation in the middle of the year.

	(b)	With reference to Fig. 3, explain the formation of the northwest monsoon and its impact on Australia from October to February.                                                                            [5]                                     ·       North hemisphere/India: High pressure [0.5], South hemisphere/Australia: Low pressure [0.5] ·       Due to the pressure difference, as wind blows from a high pressure to low pressure area [0.5], the Northeast wind [0.5] is formed. ·       As the wind crosses the equator [0.5], it changes direction/deflect left [0.5], which forms the Northwest wind [0.5]. Note : (Choose 2 out of the 3 points) ·       Moisture/ water vapour [0.5] is being picked up from the Indian Ocean [0.5] ·       Brings heavy rain to Australia [0.5] during the months of October to February [0.5].

2015 Class test

		Explain why Singapore experiences the Northeast monsoon at the end of the year.
		·       At the end of the year, the Northern hemisphere will be having winter and the air over interior Asia is cool. ·       The cool air contracts, becomes denser and sinks, creating an area of high pressure. ·       The Southern hemisphere is having summer. The warm air expands, becomes less dense and rises, creating an area of low pressure. ·       Winds blow out from high pressure to low pressure areas as Northeast monsoon winds to Singapore.
	(c)		[4]

Climate GI Answers 21st Sep

1	A group of students recorded the temperature and relative humidity every hour for twelve hours. Study Fig. 1 which shows the readings.
	(a)	Name the instrument that is used to collect the readings for relative humidity.               [1] ·       Award [1] Sling Psychrometer ·       Award [0.5] Psychrometer
	(c)	Suggest two factors that can cause the data collected for relative humidity to be inaccurate.                                                                                                                        [2] ·       Swinging the psychrometer too near the body [0.5] which picks up body heat. [0.5] ·       Wrong reading of the temperatures on the thermometers. ·       Swinging the psychrometer for too long/short (time) [0.5] which affects the evaporation rate of the temperature. [0.5] (Accept any other possible answers)
	(e)	Suggest the relationship between temperature and relative humidity using the graph created in 1(d).                                                                                                                 [1] Inverse relationship / relative humidity decreases when temperature increases / Relative Humidity increases when temperature decreases

2015 Class test

1	Students at a school in Singapore went to Gardens by the Bay in December to record temperature, rainfall and wind speed at 2pm every day for six days. The readings are shown in Fig. 1 below. Day Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Mean temperature (°C) 27.5 27.5 27.5 27.5 25 25 Rainfall (mm) 20 20 0 0 10 10 Wind speed (m/s) 2 2 2 2 2 2
	(b)	The students were testing the hypothesis ‘More rainfall is collected when the mean temperature is lower.’ How far do the readings in Fig. 1 support this hypothesis? The readings do not support the hypothesis. When the mean temperature is higher (27.5°C) on day 1 and 2, the rainfall is higher (20mm). When the mean temperature is lower on day 5 and 6 (25°C) the rainfall is lower (10mm). *** Award max 2m if data is not used.
	(c)	Describe the techniques the students could take to ensure that wind speed is obtained as accurate as possible.
		Select a location in an open area that is on high level. Place the anemometer where the wind is blowing directly at it for at least 5 seconds. Maintain the position of the anemometer. Collect three readings and find the average. *** Accept any 4 points.
	(d)	The students calculated the mean temperatures shown in Fig. 1 by taking the maximum and minimum temperatures at Gardens by the Bay. Suggest two possible reasons for the variations in their readings.
		Occurrence of human errors in reading and recording maximum and minimum temperature from the maximum and minimum thermometer. Students may be taking temperature at different spots at Gardens by the Bay that may have different type of land surface such as concrete and grassy ground, which may affect the readings. Students may be taking temperature at indoor or outdoor spots that cause temperature to vary greatly. *** Accept any plausible answer with explanation.

Plates Quiz 2 Answers 19th Sept

 ANSWERS

			[4]
		Generally found along plate boundaries Greater concentration around the Pacific ocean, forming the Pacific ring of fire Western coast of North and South America ·       Along eastern Asia passing through Japan Hotspot volcanoes can also be found in the middle of the Pacific ocean - Atlantic Ocean : stretches from north to south
		Fig. 2 On Fig. 2, label the following : ·       the vent (Change pipe to vent) ·       the crater ·       the secondary cone	[3]
	(c)	Explain how earthquakes are formed.	[4]
		When plates converge, diverge or slide past each other, the movement is not smooth. The rocks are under enormous stress and large amount of stored energy is built up, forcing the rocks to bend. The stress in the rocks becomes so tremendous that it finally causes the rocks to jerk free into new positions along the fault line. This results in the release of the stored energy in the form of seismic waves which make the ground vibrate, forming earthquake.
		Sea   Fig. 3 On Fig. 3, label the following : ·       the denser oceanic plate ·       the subduction zone ·       the oceanic trench ·       Melted magma	[4]