Fe3O4 encapsulated PEG form iron sand at wari ino beach has been successfully synthesized by co-precipitation method. The average particle size  of the nanoparticle 11,3 nm was determined by scherrer formula. Fe3O4 modification PEG 4000 was successfully encapsulated the samples  by the presence C-O-C and CH bonding that were characterized using Fourier Transform Infra Red (FTIR), X-Ray Diffraction (XRD) pattern  shows that all samples  are formed by single  phase cubic spinel magnetite  , and Scanning Electron Microscopy (SEM) shows the  high dispersion capability while encapsulated process using  PEG. The results of the characterization show that the Fe3O4 successfully encapsulated by PEG 4000.

Provinsi Maluku Utara terutama Pulau Halmahera dan sekitarnya merupakan bagian dari kerangka sistem tektonik Indonesia yang kompleks dan memiliki aktifitas tektonik yang tinggi. Daerah ini berada pada zona pertemuan lempeng Eurasia, lempeng Pasifik, lempeng Indo-Australia dan lempenglempeng kecil lainnya seperti lempeng Filipina. Sebagai akibat dari geodinamika maka daerah penelitian merupakan daerah dengan aktivitas seismisitas yang cukup tinggi, faktor utamanya karena terdapat struktur geologi berupa antiklin, sinklin, sesar naik, sesar mendatar dan sesar normal akibat aktivitas lempeng di daerah ini. Salah satu metode yang dapat digunakan untuk mengidentifikasi sesar dan jenisnya adalah metode gravitasi. Pada penelitian ini data yang digunakan adalah data observasi gravitasi satelit Topex dengan luasan area penelitian adalah 3.891,62 km 2 dalam bentuk Free Air Anomaly (FAA). Kemudian dikoreksi bouguer dan koreksi medan menghasilkan Anomali Bouguer Lengkap (ABL). Anomali regional dan residual menunjukkan korelasi yang baik dengan peta geologi daerah penelitian dalam mendeliniasi sebaran sesar dengan rentang nilai anomali positif ± 187 mGal dan anomali negatif ± -14.8 mGal. Analisis anomali Second Verticael Derivative (SVD) menunjukkan sebaran sesar di daerah penelitian adalah jenis sesar turun atau sesar normal.KATA KUNCI: anomali SVD, free air anomaly (FAA), koreksi bouguer, koreksi medan, sesar normal ABSTRACT−North Maluku, especially Halmahera Island is part of the framework of Indonesia's complex tectonic system and has a high tectonic activity. This area has the meeting zone of the Eurasia plate, the Pacific plate, the Indo-Australian plate and other small plates such as the Philippine plate. As a result of geodynamics, the research area with high seismic activity is due to many geological structures such as anticlines, synclines, upward faults, horizontal faults and normal faults due to plate activity in this area. One of the methods that can be used to identify the faults and their types is the gravity method. this study was using the gravitational observation data of the Topex satellite with an area of 3,891.62 km 2 in the form of Free Air Anomaly (FAA), which is then corrected by bouguers and field correction yields a complete Bouguer Anomaly (ABL). Regional and residual anomalies show the good correlation with the geological map of the study area in delineating the distribution of faults with a range of positive anomalies ± 187 mGal and negative anomalies ± -14.8 mGal. Second Vertical Derivatif (SVD) anomaly analysis shows that the distribution of faults in the study area is a type of normal fault.

Research on seawater intrusion has been carried out on the southern Tolonuo island, Tobelo sub-district, North Halmahera Regency, Indonesia using the Wenner-Schlumberger configuration resistivity geoelectric method supported by the Naniura NRD 300 HF tool, this study aims to determine the distribution pattern of seawater intrusion and to determine the resistivity value of each subsurface rock layer in the study area. The measurement results are processed using the RES2DINV software to obtain a 2-D pseudo resistivity section that describes the distribution value of the layer that the soil surface is shown in color images. The measurement results on line 1 show that there is seawater intrusion with a resistivity value range of 0.338 m - 2.44 m which is at 4 – 20 meters with a certain pattern, line 2 also has sea water intrusion at a depth of 5 m – 20 m with a resistivity value of 1.31 Ωm – 6.50 Ωm. On line 3, it is clear that there is a good correlation between the intersection of line 1 and line 2, where there is a low resistivity contrast on the line 1 with a stretch of 35 m – 50 m at a depth of 10 m – 20 m and the line 2 with a span of 80 m - 100 m at a depth of 10 m - 20 m. The distribution pattern of seawater intrusion from the south to the north of Tolonou Village with a wide range of up to 200 meters from residential areas from the shoreline. The research area has layers of clay rock with a resistivity value between 30 – 80 Ωm, and breccia rocks around it with a resistivity value of 100 – 200 Ωm. On the other hand, between clay and breccia there is impermeable rock which is thought to be conglomerate rock with a resistivity value of 200-500 Ωm, besides that in the study area there is also a layer suspected to be a groundwater aquifer layer with a resistivity value (ρ) 10 m.

The new economic era demands creativity that exceeds common expectations. Creative economy training such as processing pineapple, snake fruit and spices agricultural produce into wine is a breakthrough solution in increasing the economic value of a product. This insight is needed by generation Z who are leaning towards the creative economy era. The community service method covers two parts. The first is wine making training and the second is organoleptic testing of wine products. During the training process the participants were very enthusiastic in learning how to make snake fruit wine, pineapple and spices with being active in practicing and following each stage. The average results of the organoleptic test based on the level of preference for taste, aroma and color, the panelists liked the spiced wine the most by 4.73, 4.57 and 4.20 respectively. This activity was able to grow, motivate and add insight to participants in processing pineapples, snake fruit and spices into wine products as a business opportunity in the creative economy sector.

Gold mining activity at Tiabo river in the North Halmahera causes the water on the river is contaminated by mercury. The contamination mercury on the water can damage food chain and adverse consequences toward health of people, fish, and so on. The purpose of this study is to obtain the concentration of mercury contamination that was caused by gold mining activity. The water and sediment sample was obtained by purposive sampling. The characterization of concentration mercury in the water and sediment using mercury analyzer HG-300 in the wave length 253.72 nm. The result shows that mercury concentration of the water in the six and five sample point in the rainy session and the dry session respectively is <0.66 µg/L, and the mercury concentration in the sediment shows that the lower value in the upstream river was 1.2 mg/kg and the higher concentration in the middle of river was 8.94 mg/kg respectively in the rainy session. The result indicates that the contamination mercury in the moderate danger level according to the IADC/CEDA data standard.