FIELD OBSERVATION IN THIS COVID-19 VIRUS OUTBREAK

Nowadays, we’ve been fighting against Covid-19  virus Outbreak. As a Geoscientist, this condition makes us difficult to do our specialities like field observation, field trip, data acquisition, or any other fields analysis. But, little did we know that actually, we still can do field observation from our own home, but how is that possible? Yes, by using remote sensing.

Image by DEMNAS

So, What is Remote sensing actually?

Remote Sensing is a method that used to collect information about an object, a region or even a phenomenon by analyzing the data that has been collected by a device without making any direct physical contact with the object, region or phenomenon that is being studied (Lillesand and Kiefer, 1994). The device that is used for collecting data could be aircraft (with or without crew), air balloon, or even satellite. These devices will catch any electromagnetic energy that is reflected by earth’s surface in which its sources are from the sun or  its own satellite. The data that has been processed will come out as satellite imagery. Beside satellite imagery, we also can use geophysics data  from any open sources.

1. Volcanology (USGS.gov.)

Satellite imagery  of distribution Satellite of Volcano cone in Garut 

and Volcano complex in Mt. Dieng

The data of Remote Sensing for Volcanology can give us information about the shape and the distribution of eruption product like a pyroclastic deposition, flow and lava dome by looking at the specific form appeared. Besides that, the data of remote sensing can give us illustration about volcano complex and its eruption history that can be seen by the differences of erosion level, an active volcano with the distribution of pyroclastic and lava flow. 

2. Fold structure in sedimentary rock 

Fold structure in sedimentary rock shows a special appearance that can be seen by satellite imagery. These are the satellite imageries of sedimentary rocks: alluvial (A) Sandstone (B) Shale (C) Bedding of sand-clay  (D) and the slope of bedding plane northwards. 

3. Disaster hazard of mass wasting

In Satellite imagery, the symptom of mass wasting is shown by the specific shape like those that resemble to horseshoe shape, steep slope, vent pattern that parallel to landslide cliff, humidity of lower part of the cliff, the height of topography along the river cliff, etc. Although type of mass wasting can’t be specified just by satellite imagery, initial prediction can be predicted from the form of that mass wasting product. 

4. Seismic activity record (dr. Iris. Edu)

We can know seismic activity in the form of earthquake. dr. Iris. Edu provides seismic data with its occurrence time and its seismic measurement station. These data can be used to know the type of seismic that occurred and also can be used to determine the hypocenter of the earthquake.

5. Gravity (topex.uscd. edu)

Gravity method's data can be accessed freely (open source) from internet by surfing on topex.uscd.edu. Almost all data of earth’s surface region across the world can be accessed on this  website. The data in Topex are basically a regional data. Analysis function in gravity map can be used to determine fault, block, and mitigation.

REFERENCE

[1]. Noor, Djauhari. 2008. Pengantar Geologi. Bogor : Pakuan University Press

[2]. Soetoto. 2015. Penginderaan Jauh Untuk Geologi. Yogyakarta

[3]. Sutanto. 1979. Pengetahuan Dasar Interpretasi Citra. Gadjah Mada University Press. Yogyakarta

[4]. Tides.big.go.id/DEMNAS/index.html diakses pada 18 April 2020

[5]. http://ds.iris.edu/seismon/index.phtml diakses pada 21 April 2020

Fauzi & Irfan